Multiple reactor and multiple zone polyolefin polymerization

ABSTRACT

Apparatuses and processes that produce multimodal polyolefins, and in particular, polyethylene resins, are disclosed herein. This is accomplished by using two reactors in series, where one of the reactors is a multi-zone circulating reactor that can circulate polyolefin particles through two polymerization zones optionally having two different flow regimes so that the final multimodal polyolefin has improved product properties and improved product homogeneity.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to U.S.patent application Ser. No. 16/234,153 filed Dec. 27, 2018 and entitled“Multiple Reactor and Multiple Zone Polyolefin Polymerization,” whichapplication is incorporated by reference herein in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND Field of the Invention

This disclosure generally relates to the polymerization of polyolefinsin multiple reaction zones.

Background of the Invention

Polyolefins have various applications such as use in pipe, films, largeand small containers, cups, bottles, molded articles, and the like.There is an ongoing need for polyolefin compositions having improvedproperties and processability, especially when formed into theaforementioned items.

SUMMARY

A process for producing a multimodal polyolefin includes (a)polymerizing ethylene in a first reactor to produce a first polyolefin,(b) polymerizing ethylene in a first reaction mixture in a riser of asecond reactor to produce a second polyolefin, (c) passing the firstreaction mixture through an upper conduit from the riser to a separator,(d) recovering, in the separator, the second polyolefin from the firstreaction mixture, (e) passing the second polyolefin from the separatorinto a downcomer of the second reactor, optionally via a liquid barrier,(f) polymerizing ethylene in a second reaction mixture in the downcomerto produce a third polyolefin, (g) passing the second reaction mixturethrough a lower conduit from the downcomer to the riser, and (h) one of(1) after step (a) and before steps (b)-(g), receiving the firstpolyolefin into the second reactor, or (2) before step (a) and aftersteps (b)-(g), receiving the second polyolefin and the third polyolefininto the first reactor.

Another process for producing a multimodal polyolefin includes (a)polymerizing ethylene in a first reactor to produce a first polyolefin,(b) polymerizing ethylene in a first reaction mixture in a riser of asecond reactor to produce a second polyolefin contained in a riserproduct mixture, (c) passing the riser product mixture through an upperconduit from the riser to a separator, (d) recovering, in the separator,the second polyolefin from the riser product mixture, (e) passing thesecond polyolefin from the separator into a downcomer of the secondreactor, optionally via a liquid barrier, (f) polymerizing ethylene in asecond reaction mixture in the downcomer to produce a third polyolefinin a downcomer product mixture, (g) passing the downcomer productmixture through a lower conduit from the downcomer to the riser, and (h)one of (1) after step (a) and before steps (b)-(g), receiving the firstpolyolefin into the second reactor, or (2) before step (a) and aftersteps (b)-(g), receiving the second polyolefin and the third polyolefininto the first reactor.

Another process for producing a multimodal polyolefin, performed with i)a first reactor having a first polymerization zone, and ii) a secondreactor having a second polymerization zone in a riser and a thirdpolymerization zone in a downcomer, includes (a) polymerizing ethylenein the first polymerization zone to produce a first polyolefin, (b)passing a first reaction mixture upward through the secondpolymerization zone of the riser, wherein a second polyolefin isproduced in the second polymerization zone, (c) receiving the firstreaction mixture from the second polymerization zone in a separator, (d)separating, by the separator, a first polyolefin product from thereceived first reaction mixture, (e) passing the first polyolefinproduct through a barrier section of the second reactor and into thethird polymerization zone, (f) adding, in the third polymerization zone,the first polyolefin product to a second reaction mixture, (g) passingthe second reaction mixture downward through the third polymerizationzone of the downcomer, wherein a third polyolefin is produced in thethird polymerization zone, (h) repeating steps (b)-(g) n times, whereinn=1 to 100,000 and (i) one of 1) adding the first polyolefin to thesecond reactor at a location upstream of the second polymerization zonewith respect to a direction of flow of the first reaction mixture in thesecond polymerization zone, and withdrawing the multimodal polyolefinfrom the downcomer, or 2) withdrawing a portion of a second polyolefinproduct from the second reactor, adding the portion of the secondpolyolefin product to the first polymerization zone of the firstreactor, and withdrawing the multimodal polyolefin from the firstreactor.

An apparatus for producing a multimodal polyolefin includes a firstreactor configured to produce a first polyolefin, a second reactorconfigured to produce a second polyolefin and a third polyolefin, wherethe second reactor comprises a riser configured to produce the secondpolyolefin, an upper conduit having an end fluidly connected to a topportion of the riser, a separator fluidly connected to an opposite endof the upper conduit, a downcomer configured to produce the thirdpolyolefin, wherein a top portion of the downcomer is fluidly connectedto the separator, optionally via a liquid barrier in the top portion ofthe downcomer, and a lower conduit having an end fluidly connected to abottom portion of the downcomer and an opposite end fluidly connected toa bottom portion of the riser, wherein the second reactor is configuredto receive the first polyolefin from the first reactor, or, the firstreactor is configured to receive the second polyolefin and the thirdpolyolefin from the second reactor.

A multimodal polyolefin can comprise the first polyolefin (e.g., a lowmolecular weight component), the second polyolefin (e.g., anintermediate molecular weight component), and the third polyolefin(e.g., a high molecular weight component) made in accordance with anabove apparatus and/or process. The multimodal polyolefin can have oneor more of: a density in a range of from about 0.930 to about 0.970g/ml, a melt index in a range of from about 0.1 to about 30 g/10 minwhen tested under a force of 2.16 kg and at a temperature of 190° C., ahigh load melt index of from about 1 to about 45 g/10 min under a forceof 21.6 kg and a temperature of 190° C., a comonomer content in a rangeof from 0 to about 6 wt. %, a M_(w) in a range of from about 250 toabout 1,500 kg/mol, a M_(z) in a range of from about 500 to about 5,000kg/mol, a Mw/Mn in a range of from about 18 to about 52, a long chainbranching index in a range of from 0 to about 0.96, and a shear inducedcrystallization (SIC) index in a range of from about 0.15 to about 8.The multimodal polyolefin can be in the form of a polyethylene resin.

Another multimodal polyolefin in the form of a polyethylene resin canhave a low molecular weight (LMW) component, an intermediate molecularweight (IMW) component, and a high molecular weight (HMW) component;wherein the LMW component is present in an amount of from about 20 wt. %to about 75 wt. %; wherein the IMW component is present in an amount offrom about 5 wt. % to about 40 wt. %; wherein the HMW component ispresent in an amount of from about 10 wt. % to about 60 wt. %; whereinthe LMW component has a weight average molecular weight of from about 20kg/mol to about 150 kg/mol; wherein the IMW component has a weightaverage molecular weight of from about 85 kg/mol to about 350 kg/mol;wherein the HMW component has weight average molecular weight of greaterthan about 350 kg/mol; wherein the weight average molecular weight ofthe IMW component is greater than the weight average molecular weight ofthe LMW component; wherein the LMW component has a short chain branchingcontent of from about 0 to about 5 short chain branches per 1,000 carbonatoms; wherein the IMW component has a short chain branching content offrom about 0.1 to about 10 short chain branches per 1,000 carbon atoms;wherein the HMW component has a short chain branching content of fromabout 1 to about 15 short chain branches per 1,000 carbon atoms; andwherein the polyethylene resin has a magnitude of slip-stick of fromabout 300 psi to about 1,000 psi (about 2.07 MPa to about 6.89 MPa).

Another multimodal polyolefin in the form of a polyethylene resin canhave a low molecular weight (LMW) component, an intermediate molecularweight (IMW) component, and a high molecular weight (HMW) component;wherein the LMW component is present in an amount of from about 40 wt. %to about 60 wt. %; wherein the IMW component is present in an amount offrom about 5 wt. % to about 15 wt. %; wherein the HMW component ispresent in an amount of from about 30 wt. % to about 50 wt. %; whereinthe LMW component has a weight average molecular weight of from about 25kg/mol to about 65 kg/mol; wherein the IMW component has a weightaverage molecular weight of from about 100 kg/mol to about 200 kg/mol;wherein the HMW component has weight average molecular weight of fromabout 400 kg/mol to about 925 kg/mol; wherein the LMW component has ashort chain branching content of from about 0 to about 2 short chainbranches per 1,000 carbon atoms; wherein the IMW component has a shortchain branching content of from about 0.1 to about 5 short chainbranches per 1,000 carbon atoms; wherein the HMW component has a shortchain branching content of from about 2 to about 12 short chain branchesper 1,000 carbon atoms; and wherein the polyethylene resin has aresistance to slow crack growth of equal to or greater than about 3,000h, when tested in accordance with ASTM F1473, wherein the resistance toslow crack growth is defined as the polyethylene notch tensile test(PENT) failure time.

Another multi-modal polyolefin in the form of a polyethylene resin canhave a low molecular weight (LMW) component, an intermediate molecularweight (IMW) component [from riser], and a high molecular weight (HMW)component; wherein the LMW component is produced in a first reactionzone in the substantial absence of a comonomer, and wherein the LMWcomponent is present in an amount of from about 20 wt. % to about 75 wt.%; wherein the IMW component is produced in a second reaction zone inthe presence of a first amount of comonomer and a first amount ofhydrogen, and wherein the IMW component is present in an amount of fromabout 5 wt. % to about 40 wt. %; wherein the HMW component is producedin a third reaction zone in the presence of a second amount of comonomerand a second amount of hydrogen, wherein the second amount of comonomeris greater than the first amount of comonomer, wherein first amount ofhydrogen is greater than the second amount of hydrogen, and wherein theHMW component is present in an amount of from about 10 wt. % to about 60wt. %; wherein the LMW component has a weight average molecular weightof from about 20 kg/mol to about 150 kg/mol; wherein the IMW componenthas a weight average molecular weight of from about 85 kg/mol to about350 kg/mol; wherein the HMW component has weight average molecularweight of greater than about 350 kg/mol; wherein the weight averagemolecular weight of the IMW component is greater than the weight averagemolecular weight of the LMW component; wherein the LMW component has ashort chain branching content of from about 0 to about 5 short chainbranches per 1,000 carbon atoms; wherein the IMW component has a shortchain branching content of from about 0.1 to about 10 short chainbranches per 1,000 carbon atoms; wherein the HMW component has a shortchain branching content of from about 1 to about 15 short chain branchesper 1,000 carbon atoms; and wherein the polyethylene resin has an η₂₅₁(eta_251) of less than about 1.5×10³ Pa-s.

The foregoing has outlined rather broadly the features and technicaladvantages of the disclosed inventive subject matter in order that thefollowing detailed description may be better understood. The variouscharacteristics described above, as well as other features, will bereadily apparent to those skilled in the art upon reading the followingdetailed description of the preferred embodiments, and by referring tothe accompanying drawings.

DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of the disclosedprocesses and apparatuses, reference will now be made to theaccompanying drawings in which:

FIG. 1 illustrates a multiple reactor and multiple zone polyolefinpolymerization according to the disclosure, where a multi-zonecirculating reactor is connected downstream of a first reactor.

FIG. 2 illustrates another multiple reactor and multiple zone polyolefinpolymerization according to the disclosure, where a multi-zonecirculating reactor is connected upstream of a first reactor.

FIG. 3 illustrates a multi-zone circulating reactor having variousadditional aspects that can be utilized in FIG. 1 and/or FIG. 2.

FIG. 4 illustrates a multi-zone circulating reactor having variousadditional aspects that can be utilized in FIG. 1 and/or FIG. 2 and withany combination of aspects shown in FIG. 3.

FIGS. 5A and 5B illustrate cross-sectional views of embodiments of aneductor.

FIG. 5C illustrates a perspective view of a standpipe.

FIGS. 5D to 5H illustrate various aspects of the multi-zone circulatingreactor having an eductor that can be utilized in FIG. 1 and/or FIG. 2and with any combination of other aspects described herein.

FIGS. 5I and 5J illustrate embodiments of the multi-zone circulatingreactor having a standpipe that can be utilized in FIG. 1 and/or FIG. 2and with any combination of other aspects described herein.

FIG. 6A illustrates a configuration of the multi-zone circulatingreactor having a transition conduit that can be utilized in FIG. 1and/or FIG. 2, along with any combination of aspects described herein.

FIG. 6B illustrates the configuration of the multi-zone circulatingreactor in FIG. 6A, having an eductor and standpipe instead of thetransition conduit.

FIG. 6C illustrates the configuration of the multi-zone circulatingreactor in FIG. 6A, having a standpipe placed inside the transitionconduit.

FIG. 7 illustrates an isolated view of an elbow connector having a smartelbow configuration.

FIG. 8A is a side view of the separator of the multi-zone circulatingreactor, embodied as a cyclone separator.

FIG. 8B is a top cross-sectional view of the cyclone separator of FIG.8A, taken along sight line i-i shown in FIG. 8A.

FIG. 9 illustrates an embodiment of a product separation system depictedin FIG. 1 and FIG. 2.

FIG. 10A illustrates the first reactor in a gas phase configuration foruse in FIG. 1, utilizing a settling leg to move the reactor effluent toa separator for polyolefin recovery.

FIG. 10B illustrates the first reactor in a gas phase configuration foruse in FIG. 1, utilizing a lock hopper to move the reactor effluent to aseparator for polyolefin recovery.

FIG. 10C illustrates the first reactor in a gas phase configuration foruse in FIG. 1, utilizing a take-off valve to move the reactor effluentto a separator for polyolefin recovery.

FIG. 10D illustrates the first reactor in a gas phase configuration foruse in FIG. 2, utilizing a settling leg to move the reactor effluent toa separator for polyolefin recovery.

FIG. 10E illustrates the first reactor in a gas phase configuration foruse in FIG. 2, utilizing a lock hopper to move the reactor effluent to aseparator for polyolefin recovery.

FIG. 10F illustrates the first reactor in a gas phase configuration foruse in FIG. 2, utilizing a take-off valve to move the reactor effluentto a separator for polyolefin recovery.

DETAILED DESCRIPTION

Disclosed herein are apparatuses and processes for multiple reactor andmultiple zone polyolefin polymerization, as well as the polyethyleneresins that can be produced by the apparatus and processes. Thedescription may be in context of the apparatus or in context of processsteps; however, it is contemplated that aspects of the disclosed processcan include aspects discussed in apparatus context and that aspects ofthe disclosed apparatus can include aspects discussed in the processcontext. Also, while polyethylene resins are described herein, it iscontemplated that the disclosed apparatuses and processes can producevarious other polyethylene resins and otherwise various other multimodalpolyolefins by utilizing different embodiments and aspects of thediscloses apparatuses and processes.

The disclosed apparatus and processes are configured to produce amultimodal polyolefin, and particular the polyethylene resins, disclosedherein. This is accomplished by using two reactors in series, where oneof the reactors is a multi-zone circulating reactor that can implementtwo polymerization zones having two different flow regimes in order toproduce two polyolefins that have different molecular weights so thatthe final multimodal polyolefin has improved product properties,improved product homogeneity, and a reduced the number of gels comparedto a bimodal polyolefin.

The term “polyolefin” as used herein refers to unimodal or multimodalpolymers such as polyethylene, ethylene-alpha olefin copolymers,ethylene copolymers having at least about 50 percent by weight ofethylene polymerized with a lesser amount of a comonomer, polypropylene,polybutene, and other polymeric resins within the “olefin” familyclassification.

The term “unimodal” as used herein refers to a polyolefin homopolymerhaving a molecular weight distribution curve showing a single peak in amolecular weight distribution curve. Molecular weight distributioncurves can be displayed in a graph of the polyolefin weight fraction asa function of its molecular weight, as measured by, e.g., gel permeationchromatography (GPC). The polyolefin weight fraction refers to theweight fraction of polyolefin molecules of a given size.

The term “multimodal” as used herein refers to a polyolefins having amolecular weight distribution curve showing more than one peak in amolecular weight distribution curve. It is acknowledged that, in someinstances, a multimodal polyolefin may appear to have a single peak via,for example, GPC analysis, when in fact the polyolefin is multimodal,and the single peak is due to overlap of multiple peaks. The term“multimodal” includes a polyolefin having a curve showing two distinctpeaks, also referred to as a bimodal or a bimodal-like polyolefin, and apolyolefin having a curve showing three distinct peaks, also referred toas trimodal or a trimodal-like polyolefin.

The term “polymerization zone” as used herein refers to a volume ofspace inside a polymerization reactor where conditions are such that anolefin polymerization reaction occurs.

The terms “conduit” and “line” are interchangeable, and as used herein,refer to a physical structure configured for the flow of materialstherethrough, such as pipe or tubing. The materials that flow in the“conduit” or “line can be in the gas phase, the liquid phase, the solidphase, or a combination of these phases.

The term “stream” as used herein refers to a physical composition ofmaterials that flow through a “conduit” or “line”.

The term “diameter” as used herein refers to an inner diameter. Thus, apipe or conduit having a diameter disclosed herein refers to the innerdiameter of the pipe or conduit. Wall thicknesses of the pipe or conduitcan be separately specified or otherwise can be a wall thicknessappropriate for the application.

The term “length” as used herein refers to the distance of a first endof a straight section of pipe or tube to the second end of the straightsection of pipe or tube and includes any straight portions that may bepart of an elbow. For avoidance of doubt, no arcuate portions of anelbow are included in the length of an elbow.

FIG. 1 illustrates multiple reactor and multiple zone polyolefinpolymerization according to the disclosure, where a multi-zonecirculating reactor 300 is connected downstream of a first reactor 100.FIG. 2 illustrates another multiple reactor and multiple zone polyolefinpolymerization according to the disclosure, where the multi-zonecirculating reactor 300 is connected upstream of the first reactor 100.Each of the reactors 100 and 300 is a polymerization reactor configuredto polymerize one or more olefins in the presence of one or morepolymerization catalysts at conditions suitable for the production ofone or more polyolefins.

Multiple polymerization zones are present in each of FIG. 1 and FIG. 2.That is, the first reactor 100 has at least one polymerization zone 112,and the multi-zone circulating reactor 300 has two polymerization zones321 and 341. Each polymerization zone 112, 321, and 341 can beconfigured to produce a different polyolefin than the other zones. Forexample, polymerization zone 112 of the first reactor 100 can produce afirst polyolefin, second polymerization zone 321 of the MZCR 300 can beconfigured to product a second polyolefin, and third polymerization zone341 of the MZCR 300 can be configured to product a third polyolefin.Alternatively, polymerization zone 112 of the first reactor 100 can beconfigured to produce a first polyolefin and the second and thirdpolymerization zones 321 and 341 of the MCZR 300 can be configured toproduce a second polyolefin.

In aspects, the ratio of the amount of the first polyolefin produced inthe first reactor 100 that becomes part of the multimodal polyolefin tothe amount of the polyolefin(s) produced in the MZCR 300 that becomespart of the multimodal polyolefin can be about 10/90 wt. %, about 20/80wt. %, about 30/70 wt. %, about 40/60 wt. %, about 50/50 wt. %, about60/40 wt. %, about 70/30 wt. %, about 80/10 wt. %, or about 90/10 wt. %of the multimodal polyolefin.

In aspects, the ratio of the amount of the second polyolefin produced inthe riser 320 of the MZCR 300 to the amount of the third polyolefinproduced in the downcomer 340 of the MZCR 300 can be about 10/90 wt. %,about 20/80 wt. %, about 30/70 wt. %, about 40/60 wt. %, about 50/50 wt.%, about 60/40 wt. %, about 70/30 wt. %, about 80/10 wt. %, or about90/10 wt. % based on the total weight of the second polyolefin and thethird polyolefin that becomes part of the multimodal polyolefin.

FIG. 1 shows the MZCR 300 is configured to receive the first polyolefinfrom the first reactor 100. FIG. 2 shows the first reactor 100 can beconfigured to receive the second polyolefin and the third polyolefinfrom the MCZR 300.

The first reactor 100 can be embodied as one or more loop slurryreactors, one or more fluidized bed reactors, one or more autoclavereactors, one or more tubular reactors, one or more horizontal gas phasereactors, one or more continuous stirred-tank reactors, one or moresolution reactors, or a combination thereof. Configurations for thesetypes of polymerization reactors are known, each capable of having thepolymerization zone 112 that produces the first polyolefin. In anaspect, the first reactor 100 can be embodied as two or more reactorsoperated in parallel, each having a polymerization zone, and each havinga product discharge conduit 110 that feed the first reactor productmixture to a product separation system 200. In one such aspect, thepolymerization zone 112 can produce a low molecular weight (LMW)component of the multimodal polyolefin (e.g., a polyolefin resin).

Polymerization of olefin monomer and optional olefin comonomer in thefirst reactor 100 occurs by contacting a polymerization catalyst and theolefin monomer(s) in the polymerization zone 112 under polymerizationconditions. Polymerization conditions in the polymerization zone 112 caninclude a temperature ranging from about 20° C. (68° F.) to about 260°C. (500° F.) and a pressure ranging from about 14.7 psia to about 4,000psia (0.101 MPaa to about 27.6 MPaa); alternatively, a temperatureranging from about 60° C. (140° F.) to about 110° C. (230° F.) and apressure ranging from about 250 psia to about 600 psia (about 1.7 MPaato about 4.1 MPaa). In one or more aspects, polymerization in thepolymerization zone 112 can be conducted batchwise such as in acontinuous-stirred tank reactor or continuously such as in a loop slurryreactor or a gas phase reactor.

The olefin monomer polymerized in the first reactor 100 can be analiphatic 1-olefin containing from 2 to 8 carbon atoms, e.g., ethylene,propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, or 1-octene. In anembodiment, the olefin monomer is ethylene or propylene.

Polymerization of the olefin monomer can optionally be performed withone or more comonomers that are an aliphatic 1-olefin containing from 3to about 10 carbon atoms, e.g., propylene, 1-butene, 1-pentene,1-hexene, 1-pentene, 1-heptene, 1-octene, 1-nonene, or 1-decene. Inembodiments, the olefin comonomer can be ethylene, propylene, 1-butene,1-hexene, 1-octene, or a combination thereof.

Polymerization in the polymerization zone 112 can occur in the presenceof a hydrocarbon diluent that is inert to the polymerization reaction.Examples of a diluent include propane, isobutane, n-butane, n-pentane,isopentane, neopentane, n-hexane, cyclohexane, n-heptane,methylcyclohexane, or combinations thereof.

The olefin monomer used to produce the first polyolefin can be fed tothe reactor 100 via conduit 102. The optional olefin comonomer used toproduce the first polyolefin can be fed to the reactor 100 via conduit106. The diluent can be fed to the reactor 100 via conduit 104. Thepolymerization catalyst can be fed to the reactor 100 in a catalyst feedconduit 108. The polymerization catalyst can be fed via conduit 108 in asolution (e.g., catalyst dissolved in solvent liquid), in a slurry(e.g., solid catalyst particles suspended in a liquid medium such as ahydrocarbon suitable for use as the polymerization diluent), or in gasmixture (e.g., solid catalyst particles in a carrier gas such asnitrogen). Equipment such as metering valves and/or control valves canbe utilized in any of conduits 102, 104, 106, and 108 to regulate theflow of the respective component into the reactor 100.

Additional conduits can be utilized for feeding hydrogen and nitrogen tothe reactor 100. Hydrogen can be used to regulate the molecular weightof the polyolefin produced in the reactor 100. Nitrogen can be used as apressure source when controlling the pressure of the reactor 100.Additional conduits and equipment can also be utilized when reactor 100is a continuous gas phase reactor. For example, when reactor 100 is in agas phase reactor configuration that operates in condensing mode,additional conduits can be configured for recycle of gases recoveredfrom the top of the reactor 100 back to the bottom of the reactor 100 inthe form of a liquid phase. In such configuration, the conduits can beconfigured to remove gas from a top of the reactor 100, and a compressorand heat exchanger can be interconnected among the conduits andconfigured to condense and cool the gas for recycle as a liquid phaseback to the bottom of reactor 100.

In aspects, the first reactor 100 is configured to produce the firstpolyolefin such that the first polyolefin has an average residence timein the polymerization zone 112 of about 1 second to about 14 hours;alternatively, about 1 second to about 12 hours; alternatively, about 1second to about 10 hours; alternatively, about 1 second to about 8hours; alternatively, about 2 hours to about 14 hours; alternatively,about 4 hours to about 14 hours; alternatively, about 4 hours to about12 hours; alternatively, from about 1 hour to about 3 hours;alternatively, about 1 second to about 5 minutes; alternatively, lessthan 10 hours; alternatively, greater than 1 hour.

A product mixture containing polyolefin particles (e.g., the firstpolyolefin or the multimodal polyolefin) is withdrawn from the reactor100 via the product discharge conduit 110. In FIG. 1, a product mixturecontaining the first polyolefin is withdrawn from the first reactor 100via the product discharge conduit 110. FIG. 1 shows the productdischarge conduit 110 located on a bottom of the first reactor 100;however, it is contemplated that the product discharge conduit 110 canbe located anywhere on the reactor 100 of FIG. 1, such as a side of thereactor 100. In FIG. 2, a product mixture containing the multimodalpolyolefin is withdrawn from the first reactor 100 via the productdischarge conduit 110. FIG. 2 shows the product discharge conduit 110located on the side of the first reactor 100; however, it iscontemplated that the product discharge conduit 110 can be locatedanywhere on the reactor 100 of FIG. 2, such as the bottom of the reactor100. In an embodiment, the product discharge conduit 110 can include atake-off valve that is configured as a continuous take-off valve or adiscontinuous take-off valve. A continuous take-off valve can regulatethe removal of the produce mixture from the first reactor 100 such thatproduct mixture is removed on a continuous basis. A discontinuoustake-off valve can regulate the removal of the product mixture on adiscontinuous basis, for example, opening and shutting such that theflow of the product mixture through the discontinuous take-off valve isnot continuous.

In aspects, at least a portion of the reactor 100 can be made carbonsteel, stainless steel, or a combination of these materials. In afurther aspect the carbon steel can be a low temperature carbon steel.In an embodiment, an internal surface 109 of the reactor 100 can have arust inhibitor coating.

The multi-zone circulating reactor (MZCR) 300 generally polymerizesolefin monomer and optional olefin comonomer in gas phase polymerizationand has two interconnected polymerization zones 321 and 341. Thedirection of flow of the reaction mixture(s) in the MZCR 300 is shown inFIG. 1 and FIG. 2 by arrows A and B. The flow path for the reactionmixture(s) in the MCZR 300 is in the form of a loop, formed by a lowerconduit 310 fluidly connected to a riser 320, the riser 320 additionallybeing fluidly connected an upper conduit 330, the upper conduit 330additionally being fluidly connected to a downcomer 340, and thedowncomer 340 additionally being fluidly connected to the lower conduit310. A separator 350 can be fluidly connected to each of the upperconduit 330 and to a liquid barrier 360 (interchangeably referred to asa barrier section 360) of the downcomer 340.

In an aspect, the polymerization zone 321 of the riser 320 can producean intermediate molecular weight (IMW) component, and the polymerizationzone 341 of the downcomer 340 can produce a high molecular weight (HMW)component of the multimodal polyolefin (e.g., a polyethylene resin).

As illustrated in both FIG. 1 and FIG. 2, an end 312 of the lowerconduit 310 can be fluidly connected to a bottom portion 329 of theriser 320, a top portion 328 of the riser 320 can be fluidly connectedan end 331 of the upper conduit 330, the separator 350 can be fluidlyconnected to an end 332 of the upper conduit 330, the separator 350additionally can be fluidly connected to a top portion 348 of thedowncomer 340 via the liquid barrier 360 that is in the top portion 348of the downcomer 340, and a bottom portion 349 of the downcomer 340 canbe fluidly connected to the end 311 of the lower conduit 310.

An elbow connector 302 is fluidly connected to the end 312 of the lowerconduit 310 and to the bottom portion 329 of the riser 320; an elbowconnector 304 is fluidly connected to the top portion 328 of the riser320 and to an end 331 of the upper conduit 330; the separator 350 isfluidly connected to the end 332 of the upper conduit 330 and to theliquid barrier 360; the liquid barrier 360 is additionally fluidlyconnected to a top portion 348 of the downcomer 340; and an elbowconnector 306 is fluidly connected to the bottom portion 349 of thedowncomer 340 and to the end 311 of the lower conduit 310. The scope ofthis disclosure includes interpretations where the elbow connectors 302,304, and 306 are pieces of equipment that are separate from the portionsof the loop formed by the lower conduit 310, riser 320, upper conduit330, and downcomer 340. Alternatively, the scope of this disclosureincludes interpretations where the elbow connectors 302, 304, 306 areformed as part of an adjacent piece of the loop, e.g., elbow connector302 can be part of the lower conduit 310 or part of the riser 320, elbowconnector 304 can be part of the upper conduit 330 or part of the riser320, and elbow connector 306 can be part of the downcomer 340 or part ofthe lower conduit 310.

The lower conduit 310 can be embodied as a tubular structure throughwhich a reaction mixture (e.g., downcomer product mixture, optionallywith added recycled monomer, comonomer, and/or diluent) passes from end311 to end 312. The longitudinal axis of the lower conduit 310 can beoriented substantially horizontally, as shown in FIG. 1 and FIG. 2.Alternatively, the longitudinal axis of the lower conduit 310 can beoriented at an angle greater than 0° and less than 90° with respect tohorizontal, as is discussed in FIG. 4. The lower conduit 310 can have alength-to-diameter ratio of greater than about 5; alternatively, greaterthan about 10; alternatively, greater than about 15; alternatively, in arange of from about 5 to about 20. This ratio can be calculated forembodiments of the lower conduit 310 where the length of the lowerconduit 310 does not include the length of elbow connectors 302 and 306.Alternatively, this ratio can be calculated for embodiments of the lowerconduit 310 where the elbow connector 302 and/or elbow connector 306 isconsidered to be part of the lower conduit 310, and the length of thelower conduit 310 includes the length of the tubular structure that isnot curved.

The riser 320 can be embodied as a tubular structure through which thereaction mixture (e.g., beginning as the downcomer product mixture,optionally with added recycled monomer, comonomer, and/or diluent, andchanging in composition along the length of the riser 320) passes frombottom 329 to top 328. The longitudinal axis of the riser 320 can beoriented substantially vertically, as is shown in FIG. 1 and FIG. 2. Theriser 320 can have a width-to-height ratio of less than about 0.1;alternatively, less than about 0.06; alternatively, less than about0.05; alternatively, less than about 0.03; alternatively, in a range offrom about 0.03 to about 0.1. The width of the riser 320 can be thediameter of the tubular structure. The height of the riser 320 can bethe height of the polymerization zone 321. This width-to-height ratiocan be calculated for embodiments of the riser 320 where the height ofthe riser 320 does not include the height of elbow connectors 302 and304. Alternatively, this ratio can be calculated for embodiments of theriser 320 where the elbow connector 302 and/or elbow connector 304 isconsidered to be part of the riser 320, and the height of the riser 320includes the height of the tubular structure and the height of one orboth of elbow connectors 302 and 304.

The upper conduit 330 can be embodied as a tubular structure throughwhich a reaction mixture (e.g., the riser product mixture) passes fromend 331 to end 332. The longitudinal axis of the upper conduit 330 canbe oriented substantially horizontally, as shown in FIG. 1 and FIG. 2.Alternatively, the longitudinal axis of the upper conduit 330 can beoriented at an angle greater than 0° and less than 15° with respect tohorizontal, as is discussed in FIG. 10. The upper conduit 330 can have alength-to-diameter ratio of greater than about 5; alternatively, greaterthan about 10; alternatively, greater than about 15; alternatively, in arange of from about 5 to about 20. This ratio can be calculated forembodiments of the upper conduit 330 where the length of the lowerconduit 330 does not include the length of the elbow connector 304.Alternatively, this ratio can be calculated for embodiments of the upperconduit 330 where the elbow connector 304 is considered to be part ofthe upper conduit 330, and the length of the upper conduit 330 includesthe length of the tubular structure and the length of the elbowconnector 304.

The liquid barrier, or barrier section, 360 is part of the downcomer340, located in the top portion 348 of the downcomer 340 above thepolymerization zone 341. The liquid barrier 360 can be embodied as partof the tubular structure of the downcomer 340 and having a liquidtherein, through which polyolefin particles settle and subsequently flowinto the polymerization zone 341. The diameter of the tubular structureof the liquid barrier 360 can correspond to the diameter of thedowncomer 340. The height of the liquid barrier 360 can contribute tothe height of the downcomer 340. The liquid in the liquid barrier 360can be an inert liquid, in that, the liquid is inert to thepolymerization of the olefins. The inert liquid can be any of thehydrocarbons described herein that are suitable for use as a diluent(e.g., one or a combination of alkanes having 2 to 7 carbon atoms, beingstraight chain or branched, such as propane, isobutane, n-butane,n-pentane, isopentane, neopentane, n-hexane, cyclohexane, n-heptane,methylcyclohexane, or combinations thereof). In an aspect, theconcentration of the inert liquid in the liquid barrier 360 is greaterthan a concentration of the inert liquid in the downcomer 340 and in theriser 320.

The downcomer 340 can be embodied as a tubular structure through whichthe reaction mixture (e.g., changing in composition along the length ofthe downcomer 340) passes from top 348 to bottom 349. The longitudinalaxis of the downcomer 340 can be oriented substantially vertically, asis shown in FIG. 1 and FIG. 2. The downcomer 340 can have can have awidth-to-height ratio of less than about 0.1; alternatively, less thanabout 0.06; alternatively, less than about 0.05; alternatively, lessthan about 0.03; alternatively, in a range of from about 0.03 to about0.1. The width of the downcomer 340 can be the diameter of the tubularstructure. The height of the downcomer 340 can be the sum of the heightof the polymerization zone 341 and the height of the liquid barrier 360.The width-to-height ratio can be calculated for embodiments of thedowncomer 340 where the height of the downcomer 340 does not include theheight of elbow connector 306. Alternatively, this ratio can becalculated for embodiments of the downcomer 340 where the elbowconnector 306 is considered to be part of the downcomer 340, and theheight of the downcomer 340 includes the height of the tubular structureand the height of the elbow connector 306.

In an alternative aspect, the downcomer 340 can have a diameter thanvaries from top to bottom of the downcomer 340, such as a conical shape.In another alternative aspect, a portion of the downcomer 340 can have adiameter than varies from top to bottom of said portion. In such anaspect, the downcomer 340 may have another portion (e.g., a tubularstructure) above the varied portion (e.g., conical structure) and/oranother portion (e.g., a tubular structure) below the varied portion.For example, as shown in FIG. 5D, a bottom portion 349 of the downcomer340 can be conical in shape, while the remaining portion of thedowncomer 340 that is above the bottom portion 340 can be a tubularstructure. In aspects where both a portion above and a portion below thevaried portion are used, the diameter of the portion above the variedportion can be greater than the diameter of the portion below the variedportion. Without being limited by theory, it is believed that varyingthe diameter of the downcomer 340 such that the diameter decreases in avertically downward direction at least for a portion of the downcomer340 can facilitate an increase in the velocity of the polymer bed thanmoves downwardly through the downcomer 340.

Each of elbow connectors 302, 304, and 306 can be embodied as a tubularstructure that changes the direction of flow of the reaction mixture inthe MZCR 300. Elbow connector 302 can change the direction of flow ofthe reaction mixture from the direction of flow provided in lowerconduit 310 to the direction of flow in the riser 320. Elbow connector304 can change the direction of flow of the reaction mixture from thedirection of flow provided in the riser 320 to the direction of flow inthe upper conduit 330. Elbow connector 306 can change the direction offlow of the reaction mixture from the direction of flow provided in thedowncomer 340 to the direction of flow in the lower conduit 310. Theangle between the ends of each elbow connector 302, 304, 306 canindependently vary from about 45° to about 135°.

Elbow connector 302 can connect to the bottom portion 329 of the riser320 and to the end 312 of the lower conduit 310. More specifically, end302 a of the elbow connector 302 can connect to the bottom portion 329of the riser 320, and end 302 b of the elbow connector 302 can connectto the end 312 of the lower conduit 310. Elbow connector 304 can connectto the top portion 328 of the riser 320 and to the end 331 of the upperconduit 330. More specifically, end 304 a of the elbow connector 304 canconnect to the top portion 328 of the riser 320, and end 304 b of theelbow connector 304 can connect to the end 331 of the upper conduit 330.Elbow connector 306 can connect to the bottom portion 349 of thedowncomer 340 and to the end 311 of the lower conduit 310. Morespecifically, end 306 a of the elbow connector 306 can connect to thebottom portion 349 of the downcomer 340, and end 306 b of the elbowconnector 306 can connect to the end 311 of the lower conduit 310.

In an aspect, at least one of the elbow connectors 302, 304, or 306 hasan inner diameter (d) and a radius (R_(c)) of an inner curvature suchthat the elbow connector 302, 304, or 306 configured to maintain a Deannumber (D_(n)) of the reaction mixture flowing therein to be a value ina range of about 1,000,000 to about 5,000,000, whereD_(n)=ρVd/μ*(d/2R_(c))^(1/2) and where ρ is a density of the reactionmixture, V is a circulation velocity of the reaction mixture, and μ is adynamic viscosity of the reaction mixture. The density, circulationvelocity, and the dynamic viscosity are the values for the reactionmixture in the respective elbow connectors 302, 304, or 306.

The separator 350 of the MZCR 300 can be embodied as a flash tank, aflash vessel, a flash chamber, a cyclone, a high efficiency cyclone, ora centrifuge. The end 332 of the upper conduit 330 can be fluidlyconnected to the separator 350 proximate a top 354 of the separator 350.The separator 350 is configured to separate the reaction mixture (e.g.,the riser product mixture comprising solid polyolefin particles and agas mixture) received from the upper conduit 330 into polyolefinparticles and gases. The gases are removed from the separator 350 viavapor conduit 353. The polyolefin particles settle in bottom of theseparator 350 and flow downwardly through an outlet 352 of the separator350 into the liquid barrier 360.

The MZCR 300 has various feed lines that can be configured to injectcomponents of a reaction mixture for polymerization in thepolymerization zone 321 of the riser 320 and to inject components of areaction mixture for polymerization in the polymerization zone 341 ofthe downcomer 340.

FIG. 1 shows a catalyst feed line 322 configured to feed catalyst forpolymerization of an olefin in the polymerization zone 321 of the riser320. FIG. 1 also shows an olefin monomer feed line 342, an olefincomonomer feed line 343, a hydrogen feed line 344, and a diluent feedline 345 configured to feed each of the respective components to thedowncomer 340 for polymerization of one or more olefins in thepolymerization zone 341 of the downcomer 340.

FIG. 2 shows additional inlet feed lines can be configured to delivercomponents for polymerization in the polymerization zone 321 of theriser 320. An olefin monomer feed line 323, an olefin comonomer feedline 324, and a diluent feed line 345 configured to feed each of therespective components to the downcomer 340 for polymerization of one ormore olefins in the polymerization zone 321 of the riser 320.

While FIG. 1 and FIG. 2 show one feed line 322, 323, 324, 325, 342, 343,and 344 configured to inject the respective component into the riser 320and downcomer 340, it is contemplated that more than one feed line canbe used to inject any of the olefin monomer, olefin comonomer,polymerization catalyst, diluent, and hydrogen. Further, in aspectswhere multiple feed lines for a component are used, it is contemplatedthat the feed lines for a given components are placed in multiplelocations. For example, multiple comonomer feed lines 343 can be locatedat various locations on the downcomer 340 of the MZCR 300.

Alternative configurations in FIG. 1 include no feed lines for the riser320. Alternative configurations in FIG. 1 also include additional feedlines 323, 324, and 325 configured to feed components as discussed aboveinto the reaction mixture that flows through the riser 320.

The MZCR 300 includes a product discharge conduit 370 fluidly connectedto the bottom portion 349 of the downcomer 340. A product mixturecontaining polyolefin particles is withdrawn from the MZCR 300 via theproduct discharge conduit 370. In FIG. 1, a product mixture containingthe multimodal polyolefin is withdrawn from the MZCR 300 via the productdischarge conduit 370. In FIG. 2, a product mixture containing apolyolefin is withdrawn from the MZCR 300 via the product dischargeconduit 370. FIG. 1 and FIG. 2 show the product discharge conduit 370fluidly connected to a bottom portion 349 of the MZCR 300. However, itis contemplated that the product discharge conduit 370 can fluidlyconnected anywhere on the MZCR 300 of FIG. 1, such as i) to a bottomhalf of the downcomer 340, ii) on or near a bottom tangent of thedowncomer 340, or iii) somewhere along the outer radius of the elbowconnector 306 or on the lower conduit 310.

In an aspect, the bottom tangent of the downcomer 340 is the location atthe bottom of the downcomer 340 that is the tangent before any curvatureor deviation from vertical.

In aspects, the product discharge conduit 370 can be located at or abovethe bottom tangent of the downcomer 340. More specification, the productdischarge conduit 370 can be located above the bottom tangent of thedowncomer 340 for a distance that is 0% to 50% of the total height ofthe downcomer 340. In an alternative aspect, the product dischargeconduit 370 can be located on a curvature of the downcomer 340, such ason the elbow connector 306. In an alternative aspect, the productdischarge conduit 370 can be located on a curvature of the elbowconnector 306 that is connected to the downcomer 340.

In an embodiment, the product discharge conduit 370 can include atake-off valve that is configured as a continuous take-off valve or adiscontinuous take-off valve. A continuous take-off valve can regulatethe removal of the produce mixture from the MZCR 300 such that productmixture is removed on a continuous basis. A discontinuous take-off valvecan regulate the removal of the product mixture from the MZCR 300 on adiscontinuous basis, for example, opening and shutting such that theflow of the product mixture through the discontinuous take-off valve isnot continuous. In an aspect, the take-off valve can be part of thepolyolefin product separation system 400, such as take-off valve 410described in FIG. 9 below.

In an aspect, the product mixture in the product discharge conduit 370can have a concentration of solid polyolefin particles greater than 50wt. %, 60, wt. %, 70 wt. %, 80 wt. %, 90 wt. % based on a total weightof the mixture.

Polymerization conditions in the polymerization zone 321 andpolymerization zone 341 of the MZCR 300 can include the conditionssuitable for gas phase polymerization reactions. In aspects, thepolymerization zone 321 and the polymerization zone 341 can each operatewith a temperature ranging from about 50° C. (122° F.) to about 120° C.(248° F.) and a pressure ranging from about 14.7 psia to about 1,000psia (0.101 MPaa to about 6.9 MPaa).

The olefin monomer polymerized in polymerization zone 321 and/orpolymerization zone 341 of the MZCR 300 can be an aliphatic 1-olefincontaining from 2 to 8 carbon atoms, e.g., ethylene, propylene,1-butene, 1-pentene, 1-hexene, 1-heptene, or 1-octene. In an embodiment,the olefin monomer is ethylene or propylene.

Polymerization of the olefin monomer in the polymerization zone 321and/or polymerization zone 341 of the MZCR 300 can optionally beperformed with one or more comonomers that are an aliphatic 1-olefincontaining from 3 to about 10 carbon atoms, e.g., propylene, 1-butene,1-pentene, 1-hexene, 1-pentene, 1-heptene, 1-octene, 1-nonene, or1-decene. In embodiments, the olefin comonomer can be propylene,1-butene, 1-hexene, 1-octene, or a combination thereof.

Polymerization in the polymerization zone 321 and/or polymerization zone341 of the MZCR 300 can occur in the presence of a hydrocarbon diluentthat is inert to the polymerization reaction. Examples of a diluentinclude propane, isobutane, n-butane, n-pentane, isopentane, neopentane,n-hexane, cyclohexane, n-heptane, methylcyclohexane, or combinationsthereof.

A reaction mixture containing polyolefin particles and a gas mixture canflow upwardly through the second polymerization zone 321 in the riser320, through the upper conduit 330, and into the separator 350. Thereaction mixture in the riser 320 (e.g., the riser reaction mixture) canhave a gas mixture of at least two components selected from olefinmonomer, diluent, and a polymerization catalyst. The reaction mixtureexiting the riser 320 (e.g., the riser product mixture) can likewisehave a gas mixture of at least two components selected from olefinmonomer, diluent, and a polymerization catalyst.

Gases recovered from the reaction mixture (e.g., the riser productmixture) are removed from the separator 350 via vapor conduit 353, whilepolyolefin particles recovered from the reaction mixture fall to thebottom of the separator 350 and flow downwardly through an outlet 352 ofthe separator 350 into the liquid barrier 360. The polyolefin particlessettle downwardly through the liquid in the liquid barrier 360 bygravity and flow into the top 348 of the downcomer 340. The polyolefinparticles become part of a separate reaction mixture in the downcomer340.

The reaction mixture in the downcomer 340 (e.g., the downcomer reactionmixture) can have a gas mixture of at least two components selected fromhydrogen, olefin monomer, olefin comonomer, diluent, and apolymerization catalyst. The reaction mixture exiting the downcomer 340(e.g., the downcomer product mixture) can likewise have a gas mixture ofat least two components selected from hydrogen, olefin monomer, olefincomonomer, diluent, and a polymerization catalyst. The polyolefinparticles in the downcomer reaction mixture can flow through thepolymerization zone 341 of the downcomer 340 downwardly by gravity,through the lower conduit 310, and back into the polymerization zone321. A circulation of polyolefin(s) is established in the flow pathdefined by the lower conduit 310, riser 320, upper conduit 330,separator 350, downcomer 340, and any pieces of conduit consideredseparate from the lower conduit 310, riser 320, upper conduit 330, anddowncomer 340 (e.g., any connecting pieces such as elbow connectors 302,304, and 306). In an aspect, the reaction mixture in the downcomer 340(e.g., the downcomer reaction mixture) can have a gas composition thatis different than the gas composition in the riser 320 (e.g., the riserreaction mixture).

The MZCR 300 affords the flexibility that the reaction mixture of thedowncomer 340 can have a different gaseous composition than the reactionmixture in the riser 320, which advantageously provides for producingtwo different polyolefins in the MZCR 300. In this aspect, thepolyolefin particles flowing in the loop of the MZCR 300 can include thepolyolefin made in the riser 320, the polyolefin made in the downcomer340, and optionally for the order of reactors 100 and 300 shown in FIG.1, the first polyolefin produced in the first reactor 100.Alternatively, the reaction mixture of the downcomer 340 can have thesame gaseous composition as the reaction mixture in the riser 320. Thus,in this aspect, the polyolefin particles flowing in the loop of the MZCR300 can include the polyolefin made in the MZCR 300, and optionally forthe order of reactors 100 and 300 shown in FIG. 1, the polyolefinproduced in the first reactor 100. It is believed that the configurationof the MZCR 300 in combination with the first reactor 100 can improveproduct properties, improve product homogeneity, and reduce the numberof gels.

The flow in the second polymerization zone 321 in the riser 320 can beunder fast fluidization conditions. The conditions for fast fluidizationare obtained when the velocity of the fluidizing gas (e.g., the diluentand/or condensing agent) is higher than the transport velocity of thepolyolefin solids, and the pressure gradient along the direction of flowis a monotonic function of the quantity of solid, for equal flow rateand density of the fluidizing gas. In contrast, conventionalfluidized-bed technology utilized in gas phase reactors maintains thefluidizing-gas velocity well below the transport velocity, in order toavoid solids entrainment and particle carryover into the gas recyclesystem of the gas phase reactor.

The flow in the third polymerization zone 341 in the downcomer 340 canbe under plug flow conditions. The polyolefin particles can form amoving bed of solid particles that move downwardly through thepolymerization zone 341 in the downcomer 340, where polyolefin particlesexiting the bed of solid particles into the lower conduit 310 make roomfor polyolefin particles entering the bed from the liquid barrier 360.It is contemplated that a positive gain in pressure obtained by thedownward flow of the reaction mixture in the downcomer 340 can providemomentum of the polyolefin particles that is suitable to reintroduce thepolyolefin particles into the riser 320 via the lower conduit 310. Inthis way, a “loop” circulation is established. For the order of reactors100 and 300 shown in FIG. 1, the circulation back to the riser 320 canbe facilitated by one or more of: 1) the introduction of the firstpolyolefin produced in the first reactor 100 into the MCZR 300 viaconduit 202, 2) the introduction of one or more of unreacted olefinmonomer, unreacted olefin comonomer, and diluent via conduit 502 and/orconduit 503. For the order of reactors 100 and 300 shown in FIG. 2, thecirculation back to the riser 320 can be facilitated by the introductionof one or more of unreacted olefin monomer, unreacted olefin comonomer,and diluent via conduit 502 and/or conduit 503. Alternative oradditional embodiments of the MZCR 300 can include equipment forfacilitating the recirculation of the polyolefin particles from thedowncomer 340 to the riser 320, such as the eductor 375 shown in FIGS.5A, 5B, 5D-5H, and 6B and/or standpipe shown in FIGS. 5C, 5I, 5J, and6B-6C.

In an aspect, the polyolefin particles of the moving bed of solidparticles can have a packed bed configuration. That is, the polyolefinparticles can have a high concentration in the mixture of solids andgas/liquid moving through the downcomer 340 as compared to theconcentration of gas and/or liquid that is contained in the mixture. Theconcentration of solid polyolefin particles in the moving mixture can begreater than 50 wt. %, 60, wt. %, 70 wt. %, 80 wt. %, 90 wt. % based ona total weight of the mixture (e.g., based on a “plug” of the movingmixture). An advantage of having a high concentration of polyolefinparticles in the mixture is that the portion(s) of the mixture removedin the product discharge conduit 370 require smaller capacity fordownstream equipment configured to separate the polyolefin particlesfrom the gas and any liquid.

In aspects, the lower conduit 310 can be configured such that thereaction mixture (e.g., the downcomer product mixture, optionally withadded recycled components) can flow in the lower conduit 310 at avelocity that is i) greater than a saltation velocity of the reactionmixture and up to about 30.48 m/s (100 ft/sec), ii) i) greater than asaltation velocity of the reaction mixture and greater than about 0.508m/s (20 ft/sec), iii) greater than a saltation velocity of the reactionmixture and greater than about 0.762 m/s (30 ft/sec), iv) greater than asaltation velocity of the reaction mixture and greater than about 1.016m/s (40 ft/sec), v) greater than a saltation velocity of the reactionmixture and greater than about 1.27 m/s (50 ft/sec), vi) greater than asaltation velocity of the reaction mixture and greater than about 1.52m/s (60 ft/sec), vi) from about 1.52 m/s (60 ft/sec) to about 30.48 m/s(100 ft/sec), vii) from about 0.762 m/s (30 ft/sec) to about 1.27 m/s(50 ft/sec), or viii) greater than 110% of the saltation velocity of thereaction mixture. In further aspects of the disclosure, the upperconduit 330 is configured such that the reaction mixture (e.g., theriser product mixture) can flow in the upper conduit 330 at a velocitythat is i) greater than a saltation velocity of the reaction mixture andup to about 30.48 m/s (100 ft/sec), ii) i) greater than a saltationvelocity of the reaction mixture and greater than about 0.508 m/s (20ft/sec), iii) greater than a saltation velocity of the reaction mixtureand greater than about 0.762 m/s (30 ft/sec), iv) greater than asaltation velocity of the reaction mixture and greater than about 1.016m/s (40 ft/sec), v) greater than a saltation velocity of the reactionmixture and greater than about 1.27 m/s (50 ft/sec), vi) greater than asaltation velocity of the reaction mixture and greater than about 1.52m/s (60 ft/sec), vi) from about 1.52 m/s (60 ft/sec) to about 30.48 m/s(100 ft/sec), vii) from about 0.762 m/s (30 ft/sec) to about 1.27 m/s(50 ft/sec), or viii) greater than 110% of the saltation velocity of thereaction mixture.

Circulation of polyolefin particles in the loop of the MZCR 300 can beabout 50 to about 250 times the multimodal polyolefin production rate.In aspects, the polyolefin particles can circulate the loop from 1 toabout 250 cycles before being withdrawn from the MZCR 300. In aparticular aspect, the polyolefin particles can circulate about 40, 50,60, 70, 80, 90, or 100 cycles before being withdrawn from the MZCR 300.In aspects, the time for a polyolefin particle to circulate the loop ofthe MZCR 300 can be from about 0.5 minutes to about 10 minutes;alternatively, about 1 minute to about 8 minutes; alternatively, about 1minute to about 7 minutes; alternatively, about 1 minute to about 6minutes; alternatively, about 1 minute to about 5 minutes;alternatively, about 1 minute to about 4 minutes; alternatively, about 1minute to about 3 minutes; alternatively, about 1 minute to about 2minutes; alternatively, about 2 minutes to about 3 minutes;alternatively, about 2 minutes.

In aspects, the average residence time of polyolefin particles in theMZCR 300 can range from about 0.25 hours to about 5 hours;alternatively, about 0.5 hours to about 4 hours; alternatively, about 1hour to about 3 hours; alternatively, about 2 hours. In aspects, theaverage residence time of the riser reaction mixture in thepolymerization zone 321 of the riser 320 during a single pass throughthe polymerization zone 321 is in a range of about 1 second to about 5minutes. In additional aspects, the residence time of the downcomerreaction mixture in the polymerization zone 341 of the downcomer 340during a single pass through the polymerization zone 341 is in a rangeof about 5 second to about 15 minutes. The polyolefin particles can becirculated in the loop of the MZCR 300 from 1 to about 100,000 cycles.The total average residence time of polyolefin particles in the MZCR 300can be on the order of hours.

In aspects, at least a portion of the MZCR 300 can be made carbon steel,stainless steel, or a combination of these materials. In a furtheraspect the carbon steel can be a low temperature carbon steel.

In an aspect, an internal surface 379 of the MZCR 300, and optionallyany flanges of the MZCR 300, can have a rust inhibitor coating. The rustinhibitor coating can be applied during manufacture of the components ofthe MZCR 300 and be configured to inhibit rust of the components, forexample, during transport to and assembly at a plant site.

In an aspect, the internal surface 379 of the MZCR 300 can be polishedto a root mean square of less than about 3.8 microns (150 microinches);alternatively, less than about 2.54 microns (100 microinches);alternatively, less than about 1.27 microns (50 microinches);alternatively, in a range of from about 0.254 m (10 microinches) toabout 1.27 microns (50 microinches).

In an aspect, only the internal surface of the downcomer 340 of the MZCR300 is polished to a root mean square value disclosed herein;alternatively, only the internal surface of the riser 320 of the MZCR300 is polished to a root mean square value disclosed herein;alternatively, only the internal surfaces of the downcomer 340 and theriser 320 are polished to a root mean square value disclosed herein. Inan additional aspect, the internal surface 109 of the first reactor 100can be polished to a root mean square value disclosed herein.

The multiple zone polyolefin polymerization in FIG. 1 and in FIG. 2 alsocan include polyolefin product separation systems 200 and 400. FIG. 1and FIG. 2 generally illustrate that one of reactors 100 and 300 isupstream of the other. The product separation system 200 is configuredto recover polyolefin product from the product mixture withdrawn fromthe upstream reactor and between the reactors 100 and 300 such that thepolyolefin produced in the upstream reactor can be fed to the downstreamreactor. The product separation system 400 is configured to recovery themultimodal polyolefin from the product mixture withdrawn from thedownstream reactor.

The product separation system 200 can be configured to separate one ormore components in the product mixture (e.g., unreacted monomer,unreacted comonomer, diluent, catalyst, co-catalyst, or combinationsthereof) from the polyolefin produced in the upstream reactor such thatthe amount of these components fed to the downstream reactor iscontrolled, which can affect the composition of the polymerizationzone(s) in the downstream reactor.

In FIG. 1, the product separation system 200 is configured to receive aproduct mixture containing the first polyolefin via the productdischarge conduit 110, and to separate gaseous components of the productmixture from the first polyolefin. The gaseous components can includeone or more of unreacted olefin monomer, unreacted olefin comonomer,diluent, hydrogen, nitrogen, and any additive for the polymerization ofthe olefin monomer in the first reactor 100. The gaseous components canflow from the product separation system 200 in conduit 201. The firstpolyolefin can flow in conduit 202 for injection into the MZCR 300.

In FIG. 2, the product separation system 200 is configured to receive aproduct mixture containing the second polyolefin and the thirdpolyolefin via the product discharge conduit 370, and to separategaseous components of the product mixture from the second and thirdpolyolefins. The gaseous components can include one or more of unreactedolefin monomer, unreacted olefin comonomer, diluent, hydrogen, nitrogen,and any additive for the polymerization of the olefin monomer in theMZCR 300. The gaseous components can flow from the product separationsystem 200 in conduit 201. The second and third polyolefins can flow inconduit 202 for injection into the first reactor 100.

More detailed embodiments and aspects of the product separation system200 are discussed for FIGS. 10A to 10C.

The product separation system 400 is configured to recover themultimodal polyolefin product of this disclosure from the effluent ofwhichever reactor 100 or 300 is the downstream reactor (e.g., the MZCR300 in FIG. 1 or the first reactor 100 in FIG. 2). The productseparation system 400 can be configured to separate one or morecomponents in the reaction effluent (e.g., unreacted monomer, unreactedcomonomer, diluent, catalyst, co-catalyst, or combinations thereof) fromthe multimodal polyolefin. The multimodal polyolefin can then be furthertreated, sent to a container, processed (e.g., processed into pellets),or a combination thereof.

In FIG. 1, the first polyolefin is circulated in the MZCR 300 in thereaction mixtures which flow through the riser 320 and the downcomer340, so that the second polyolefin is formed in the riser 320 and thethird polyolefin is formed in the downcomer 340 in the presence of thefirst polyolefin to produce a multimodal polyolefin of this disclosure.In FIG. 1, the product separation system 400 is configured to receive aproduct mixture containing the multimodal polyolefin via the productdischarge conduit 370, and to separate the gaseous components of theproduct mixture from the multimodal polyolefin. The gaseous componentscan include one or more of unreacted olefin monomer, unreacted olefincomonomer, diluent, hydrogen, anti-static agent, nitrogen, and anyadditive for the polymerization of the olefin monomer in the MZCR 300.

In its simplest form, the product separation system 400 can beconfigured to separate polyolefin particles from the gaseous componentssuch that the multimodal polyolefin flows in conduit 401 and the gaseouscomponents flow in another conduit for fluidly coupled for recycle ofthe components back to the first reactor 100 and/or the MZCR 300. FIG. 1and FIG. 2 show an alternative recovery in that the product separationsystem 400 can be configured to separate polyolefin particles from thegaseous components, and the gaseous components can be separated from oneanother. The multimodal polyolefin can flow in conduit 401 fortransport, storage, or processing (e.g., treatment). The productseparation system 400 can be configured to separate the gaseouscomponents into olefin monomer that flows in conduit 402, olefincomonomer that flows in conduit 403, diluent that flows in conduit 404,hydrocarbons that are heavier than the diluent that flow in heaviesconduit 405, and light gases that are lighter than the unreacted monomerthat flow in a waste gas conduit 406.

In FIG. 2, the first polyolefin is formed in the first reactor 100 inthe presence of the second and third polyolefins to produce a multimodalpolyolefin of this disclosure. In FIG. 2, the product separation system400 is configured to receive a product mixture containing the multimodalpolyolefin via the product discharge conduit 110, and to separate thegaseous components of the product mixture from the multimodalpolyolefin. The gaseous components can include one or more of unreactedolefin monomer, unreacted olefin comonomer, diluent, hydrogen,anti-static agent, nitrogen, and any additive for the polymerization ofthe olefin monomer in the first reactor 100. The multimodal polyolefincan flow in conduit 401 for transport, storage, or processing (e.g.,treatment). Like that shown in FIG. 1, the product separation system 400of FIG. 2 can separate the gaseous components from one another. In anaspect, the product separation system 400 can separate the gaseouscomponents into olefin monomer that flows in conduit 402, olefincomonomer that flows in conduit 403, diluent that flows in conduit 404,hydrocarbons that are heavier than the diluent flow in heavies conduit405, and light gases that are lighter than the unreacted monomer flow inwaste gas conduit 406.

More detailed embodiments and aspects of the product separation system400 are described for FIG. 9.

In both FIG. 1 and FIG. 2, the vapor recycle system 500 is configured torecycle gases recovered from the separator 350 of the MZCR 300. Gasesflow in vapor conduit 353 and into the vapor recycle system 500. Thevapor recycle system 500 can be configured to condense at least aportion of the gases in the vapor conduit 353 (e.g., using a compressor,heat exchanger, or both) such that liquid diluent can optionally flow tothe liquid barrier 360 in diluent recycle conduit 345. The vapor recyclesystem 500 can also be configured to recycle other gases recovered fromthe vapor conduit 353 back to the MZCR 300 via conduits 501, 502, and503. Particularly, unreacted monomer and optionally unreacted comonomercan be recycled back to the MZCR 300 at the elbow connector 306 viaconduit 502 and at the elbow connector 302 via conduit 503. Inembodiments, the vapor recycle system 500 can be configured similar to agas recycle system of a gas phase reactor such as that described forFIGS. 10A to 10C. The vapor recycle system 500 can be configured tocondense the diluent for use in the liquid barrier 360 while leaving theunreacted monomer and optional unreacted comonomer in the gas phase.

Having separately described each of the first reaction 100, productseparation system 200, MZCR 300, product separation system 400, andvapor recycle system 500 above, the process flow of the multiple zonepolymerizations in FIG. 1 and in FIG. 2 is now discussed.

In FIG. 1, the first reactor 100 is operated under polymerizationconditions so as to produce the first polyolefin in the polymerizationzone 112. Product separation system 200 is configured to receive aproduct mixture from the first reactor 100 via the product dischargeconduit 110 and to separate gaseous components in the product mixturefrom the first polyolefin in the product mixture. The gaseous componentscan flow from the product separation system 200 via conduit 201 forfurther separation, for recycling to the first reactor 100, orcombination thereof. The first polyolefin can flow from the productseparation system 200 via conduit 202. The MZCR 300 can be configured toreceive the first polyolefin, for example, in the elbow connector 302 orin the lower conduit 110. The MZCR 300 can circulate the firstpolyolefin in one or more reaction mixtures through the loop of the MZCR300 (discussed above), while operating under polymerization conditionsto concurrently produce polyolefin(s) in the polymerization zone 321 ofthe riser 320 and in the polymerization zone 341 of the downcomer 340.The vapor recycle system 500 is configured to recycle diluent, unreactedmonomer, and any unreacted comonomer recovered from the separator 350 ofthe MZCR 300 back to the elbow connector 302 and elbow connector 306 ofthe MZCR 300. The resulting polymer that is comprised of the firstpolyolefin produced in the first reactor 100 and the polyolefin(s)produced in the riser 320 and downcomer 340 of the MZCR 300 is themultimodal polyolefin product of the disclosure. The MZCR 300 isconfigured to discharge the multimodal polyolefin via the productdischarge conduit 370. Product separation system 400 is configured toreceive the product mixture from the MZCR 300 via the product dischargeconduit 370 and to separate gaseous components in the product mixturefrom the multimodal polyolefin in the product mixture. The multimodalpolyolefin can flow from the product separation system 400 via conduit401. The gaseous components can flow from the product separation system400 via conduits 402, 403, 404, 405, and 406, for further use such astreatment and/or for recycle to the first reactor 100 and/or the MZCR300.

In FIG. 2, the MZCR 300 can circulate polyolefin particles through theloop of the MZCR 300 in the various reaction mixtures (discussed above,e.g., downcomer reaction mixture, downcomer product mixture, riserreaction mixture, and riser product mixture), while operating underpolymerization conditions to produce one or more polyolefins in thepolymerization zone 321 of the riser 320 and in the polymerization zone341 of the downcomer 340. The vapor recycle system 500 is configured torecycle diluent, unreacted monomer, and any unreacted comonomerrecovered from the separator 350 of the MZCR 300 back to the elbowconnector 302 and elbow connector 306 of the MZCR 300. Productseparation system 200 is configured to receive a product mixture fromthe MZCR 300 via the product discharge conduit 370 and to separategaseous components in the product mixture from the polyolefin(s) in theproduct mixture. The gaseous components can flow from the productseparation system 200 via conduit 201 for further separation, forrecycling to the MZCR 300, or combination thereof. The polyolefin(s) canflow from the product separation system 200 via conduit 202. The firstreactor 100 can be configured to receive the polyolefin(s). The firstreactor 100 is operated under polymerization conditions so as to producethe first polyolefin in the polymerization zone 112 in the presence ofthe polyolefin(s) produced in the MZCR 300. The resulting polymer thatis comprised of the first polyolefin produced in the first reactor 100and the polyolefin(s) produced in the riser 320 and downcomer 340 of theMZCR 300 is the multimodal polyolefin product of the disclosure. Thefirst reactor 100 is configured to discharge the multimodal polyolefinvia the product discharge conduit 110. Product separation system 400 isconfigured to receive the product mixture from the first reactor via theproduct discharge conduit 110 and to separate gaseous components in theproduct mixture from the multimodal polyolefin in the product mixture.The multimodal polyolefin can flow from the product separation system400 via conduit 401. The gaseous components can flow from the productseparation system 400 via conduits 402, 403, 404, 405, and 406, forfurther use such as treatment and/or for recycle to the first reactor100 and/or the MZCR 300.

In an aspect, an amount of from about 20 to about 80 wt. %,alternatively from about 40 to about 60 wt. %, alternatively from about45 to about 55 wt. %, alternatively about 50 wt. % of the multimodalpolyolefin can comprise the first polyolefin produced in the firstreactor 100 and an amount of from about 80 to about 20 wt. %,alternatively from about 60 to about 40 wt. %, alternatively from about55 to about 45 wt. %, alternatively about 50 wt. % of the multimodalpolyolefin can comprise the second polyolefin and the third polyolefinproduced in the MZCR 300.

The concentration of the olefin monomer, olefin comonomer, hydrogen, orcombinations thereof can differ between the first reactor 100 and theMZCR 300. Moreover, the concentration of the olefin monomer, olefincomonomer, hydrogen, or combinations thereof can differ between theriser 320 and the downcomer 340 of the MZCR. In an aspect, theconcentration of the olefin monomer (e.g., ethylene, propylene, orbutene) in the first reactor 100 can be from 0.1 to 10 wt. % onsolids-free basis (i.e., the basis is the amount of gas or liquid to theexclusion of any solid polyolefin particles); the concentration of theolefin comonomer (e.g., 1-butene, 1-hexene, or 1-octene) in the firstreactor 100 can be from 0.0 to 5 wt. % on a solids-free basis; theconcentration of hydrogen in the first reactor 100 can be from 0.0 toabout 5 mole % on a solids-free basis; or a combination thereof. In anaspect, the concentration of the olefin monomer (e.g., ethylene,propylene, or butene) in the MZCR 300 can be from 0.1 to 10 wt. % onsolids-free basis (i.e., the basis is the amount of gas or liquid to theexclusion of any solid polyolefin particles); the concentration of theolefin comonomer (e.g., 1-butene, 1-hexene, or 1-octene) in the MZCR 300can be from 0.0 to 5 wt. % on a solids-free basis; the concentration ofhydrogen in the MZCR 300 can be from 0.0 to about 5 mole % on asolids-free basis; or a combination thereof. In aspects, theconcentration of olefin monomer in the first reactor 100 can vary in therange disclosed above; the concentration of olefin comonomer in thefirst reactor 100 can vary in the range disclosed above; theconcentration of hydrogen in the first reactor 100 can vary in the rangedisclosed above; the concentration of olefin monomer in the MZCR 300 canvary in the range disclosed above; the concentration of olefin comonomerin the MZCR 300 can vary in the range disclosed above; the concentrationof hydrogen in the MZCR 300 can vary in the range disclosed above; orcombination thereof.

In a particular aspect, the concentration of olefin monomer (e.g.,ethylene, propylene, or butene) in the first reactor 100 can have from 1to 6 wt. % ethylene, 0.0 to 1 wt. % olefin comonomer, and no hydrogen ona solids-free basis; the riser 230 of the MZCR 300 can have 2 to 10 wt.% ethylene, 0.1 to 3 wt. % olefin comonomer, and 0.2 to 2 mole %hydrogen on a solids-free basis; and the downcomer 340 of the MZCR 300can have 3 to 20 wt. % ethylene, 0.5 to 8 wt. % olefin comonomer, and0.0 to 0.5 mole % hydrogen.

In an aspect, the concentration of ethylene can be lowest in the firstreactor 100 or in the downcomer 340 of the MZCR 300. In another aspect,the concentration of ethylene can be greatest in the first reactor 100or in the riser 320 of the MZCR 300.

In an aspect, the concentration of hydrogen in the first reactor 100 canbe greater than the concentration of hydrogen in the riser 320 of theMZCR 300, and the concentration of hydrogen in the riser 320 of the MZCR300 can be greater than the concentration of hydrogen in the downcomer340 of the MZCR 300.

In an aspect, the concentration of olefin comonomer in the first reactor100 can be less than the concentration of olefin comonomer in riser 320of the MZCR 300, and the concentration of olefin comonomer in the riser320 of the MZCR 300 can be less than the concentration of the olefincomonomer in the downcomer 340 of the MZCR 300.

As discussed for the first reactor 100, hydrogen can be used to regulatethe molecular weight of the polyolefin produced in the MZCR 300. In anaspect, the concentration of hydrogen in the first reactor 100 can bedifferent than the concentration of hydrogen in the MZCR 300. Forexample, the concentration of hydrogen in the first reactor 100 can belower than the concentration of hydrogen in at least a part of the MZCR300 (e.g., the downcomer 340). Additionally, the concentration ofhydrogen in the MZCR 300 can be different in different parts of the MZCR300 (e.g., a first concentration in the riser 320 and a secondconcentration in the downcomer 340).

In an aspect, the concentration of hydrogen can be on a gradient along aflow path in the MZCR 300. For example, the concentration of hydrogencan decrease in a downward direction in the downcomer 340 downstream ofthe injection point for hydrogen feed line 344; the concentration ofhydrogen can decrease in an upward direction in the riser 320; theconcentration of hydrogen can decrease in the direction of arrow A inthe lower conduit 310; the concentration of hydrogen can decrease in thedirection of arrow B in the upper conduit 330; or combinations thereof.

In an aspect, the concentration of comonomer in the first reactor 100can be different than the concentration comonomer in the MZCR 300. Forexample, the concentration of comonomer in the first reactor 100 can belower than the concentration of comonomer in at least a part of the MZCR300 (e.g., the downcomer 340). Additionally, the concentration ofcomonomer in the MZCR 300 can be different in different parts of theMZCR 300 (e.g., a first concentration in the riser 320 and a secondconcentration in the downcomer 340).

In an aspect, the concentration of comonomer can be on a gradient alonga flow path in the MZCR 300. For example, the concentration of comonomercan decrease in a downward direction in the downcomer 340 downstream ofthe injection point for comonomer feed line 343; the concentration ofcomonomer can decrease in an upward direction in the riser 320; theconcentration of comonomer can decrease in the direction of arrow A inthe lower conduit 310; the concentration of comonomer can decrease inthe direction of arrow B in the upper conduit 330; or combinationsthereof.

Catalyst(s)

One or more polymerization catalyst can be used to polymerize olefinmonomer(s) in the reactor 100 and in the MZCR 300. The polymerizationcatalyst can be delivered to the reactor 100 or MZCR 300 in solution(e.g., catalyst dissolved in a solvent liquid), in suspension (e.g., aslurry of the catalyst in a carrier liquid), or in gaseous mixture(e.g., a mixture of particulate catalyst in a carrier gas).

Each polymerization catalyst used to polymerize olefin(s) in the reactor100 and/or MZCR 300 can be a transition metal-based catalyst system. Thetransition metal(s) included in the transition metal-based catalystsystems can be selected from Groups IIIB, IVB, VB, VIB, VIIB, or VIIIB.More particularly, the transition metal(s) included in the transitionmetal-based catalyst systems can be selected from nickel, chromium,titanium, zirconium, hafnium, vanadium, or a combination thereof.Examples of such catalyst systems include, but are not limited to,Ziegler-Natta based catalyst systems (e.g., Ziegler-based catalystsystems), chromium-based catalyst systems, metallocene-based catalystsystems, Phillips catalyst systems, coordination compound catalystsystems, post-metallocene catalyst systems, and the like, includingcombinations thereof.

The transition metal-based catalyst system can include a solid oxidesupport for the transition metal compounds. The solid oxide used toproduce the support can comprise oxygen and one or more elements fromGroups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 of the PeriodicTable of Elements, or can comprise oxygen and one or more elements fromthe lanthanide or actinide elements. For instance, the solid oxide cancomprise oxygen and at least one element selected from Al, B, Be, Bi,Cd, Co, Cr, Cu, Fe, Ga, La, Mn, Mo, Ni, Sb, Si, Sn, Sr, Th, Ti, V, W, P,Y, Zn, and Zr. Examples of solid oxide materials that can be used toform the activator-support can include, but are not limited to, Al₂O₃,B₂O₃, BeO, Bi₂O₃, CdO, Co₃O₄, Cr₂O₃, CuO, Fe₂O₃, Ga₂O₃, La₂O₃, Mn₂O₃,MoO₃, NiO, P₂O₅, Sb₂O₅, SiO₂, SnO₂, SrO, ThO₂, TiO₂, V₂O₅, WO₃, Y₂O₃,ZnO, ZrO₂, and the like, including mixed oxides thereof, andcombinations thereof. This includes co-gels or co-precipitates ofdifferent solid oxide materials. Accordingly, the solid oxide cancomprise silica, alumina, silica-alumina, silica-coated alumina,aluminum phosphate, aluminophosphate, heteropolytungstate, titania,zirconia, magnesia, boria, zinc oxide, any mixed oxide thereof, or anycombination thereof. The silica-alumina which can be used typically canhave an alumina content from about 5 to about 95% by weight. In oneembodiment, the alumina content of the silica-alumina can be from about5 to about 50%, or from about 8% to about 30%, alumina by weight. Inanother embodiment, high alumina content silica-alumina compounds can beemployed, in which the alumina content of these silica-alumina compoundstypically can range from about 60% to about 90%, or from about 65% toabout 80%, alumina by weight. According to yet another embodiment, thesolid oxide component can comprise alumina without silica, and accordingto another embodiment, the solid oxide component can comprise silicawithout alumina. Moreover, as provided hereinabove, the solid oxide cancomprise a silica-coated alumina. The solid oxide can have any suitablesurface area, pore volume, and particle size, as would be recognized bythose of skill in the art.

In another or additional aspect, the solid oxide support can be treatedwith an electron-withdrawing component. The electron-withdrawingcomponent used to treat the solid oxide so as to form theactivator-support can be any component that increases the Lewis orBrønsted acidity of the solid oxide upon treatment (as compared to thesolid oxide that is not treated with at least one electron-withdrawingcomponent). According to one aspect, the electron-withdrawing componentcan be an electron-withdrawing anion derived from a salt, an acid, orother compound, such as a volatile organic compound, that serves as asource or precursor for that anion. Examples of electron-withdrawinganions can include, but are not limited to, sulfate, bisulfate,fluoride, chloride, bromide, iodide, fluorosulfate, fluoroborate,phosphate, fluorophosphate, trifluoroacetate, triflate, fluorozirconate,fluorotitanate, phospho-tungstate, and the like, including mixtures andcombinations thereof. In addition, other ionic or non-ionic compoundsthat serve as sources for these electron-withdrawing components also canbe employed. It is contemplated that the electron-withdrawing componentcan comprise sulfate, bisulfate, fluoride, chloride, bromide, iodide,fluorosulfate, fluoroborate, phosphate, fluorophosphate,trifluoroacetate, triflate, fluorozirconate, fluorotitanate, and thelike, or combinations thereof. Specific examples of theactivator-support include, but are not limited to, fluorided alumina,chlorided alumina, bromided alumina, sulfated alumina, fluoridedsilica-alumina, chlorided silica-alumina, bromided silica-alumina,sulfated silica-alumina, fluorided silica-zirconia, chloridedsilica-zirconia, bromided silica-zirconia, sulfated silica-zirconia,fluorided silica-titania, fluorided silica-coated alumina, sulfatedsilica-coated alumina, phosphated silica-coated alumina, and the like,as well as any mixture or combination thereof.

In additional aspects, the transition metal-based catalyst system cancomprise an activator selected from an aluminoxane compound (e.g.,methylaluminoxane), an organoboron compound, an organoborate compound(e.g., borate), an ionizing ionic compound, the solid oxide supporttreated with an electron-withdrawing component (referred to as anactivator support), the like, or any combination thereof.

In additional aspects, the transition metal-based catalyst system caninclude one or more co-catalysts. Commonly used polymerizationco-catalysts can include, but are not limited to, metal alkyl, ororganometal, co-catalysts, with the metal encompassing boron, aluminum,zinc, and the like. Representative boron-containing co-catalystsinclude, but are not limited to, tri-n-butyl borane, tripropylborane,triethylborane, and combinations thereof. Representativealuminum-containing co-catalysts can include, but are not limited to,the organoaluminum compounds of trimethylaluminum, triethylaluminum,tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum,tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride,diethylaluminum ethoxide, diethylaluminum chloride, and the like, aswell as any combination thereof. Representative zinc-containingco-catalysts include, but are not limited to, diethylzinc.

Each of the polymerization zones 112, 321, and 341 can independently useany one or a combination of the polymerization catalysts disclosedherein. In an aspect of the multiple zone polymerization which producesthe multi-modal polyolefin disclosed herein, a Ziegler-Natta catalystcan be used in each of the polymerization zone 112 of the first reactor100, the polymerization zone 321 of the riser of the MZCR 300, and thepolymerization zone 341 of the downcomer 340 of the MZCR. In analternative aspect of the multiple zone polymerization, a chromium-basedcatalyst can be used in each of the polymerization zone 112 of the firstreactor 100, the polymerization zone 321 of the riser of the MZCR 300,and the polymerization zone 341 of the downcomer 340 of the MZCR. In analternative aspect of the multiple zone polymerization, a metallocenecatalyst can be used in each of the polymerization zone 112 of the firstreactor 100, the polymerization zone 321 of the riser of the MZCR 300,and the polymerization zone 341 of the downcomer 340 of the MZCR. In analternative aspect of the multiple zone polymerization, a chromium-basedcatalyst, a Ziegler-Natta catalyst, or a metallocene catalyst can beused in the polymerization zone 112 of the first reactor 100; incombination with a chromium-based catalyst, a Ziegler-Natta catalyst, ora metallocene catalyst used in the polymerization zone 321 of the riserof the MZCR 300; in combination with a chromium-based catalyst, aZiegler-Natta catalyst, or a metallocene catalyst used in thepolymerization zone 341 of the downcomer 340 of the MZCR. In aparticular aspect, a chromium-based catalyst can be used in thepolymerization zone 112 of the first reactor 100, in combination with aZiegler-Natta or metallocene catalyst in the polymerization zone 321 ofthe riser, in combination with a Ziegler-Natta or metallocene catalystin the polymerization zone 341 of the downcomer 340.

FIG. 3 illustrates the MZCR 300 having various additional aspects thatcan be utilized in the MZCR 300 of FIG. 1 and/or FIG. 2. Feed lines 323,324, and 325 are shown with dashed lines to indicate the optional use ofthese lines, since it is intended that the aspects and embodiments ofthe MZCR 300 shown in FIG. 3 can be implemented in the MCZR 300 shown inFIG. 1 and/or FIG. 2.

In embodiments, the MZCR 300 can include a heat apparatus 371 configuredto add or remove heat from the riser 320 and/or a heat apparatus 372configured to add or remove heat from the downcomer 340. The heatapparatus 371 and/or the heat apparatus 372 can be embodied as heatexchange jackets and/or an electric heater placed around the riser 320and around the downcomer 340, respectively.

During startup of the MZCR 300, the heat apparatus 371 and/or the heatapparatus 372 can be configured to supply heat to the riser 320 and/orto the downcomer 340, respectively, in order raise the temperature ofthe polymerization zone 321 and/or polymerization zone 341 to thetemperature for polymerization. When embodied as heat exchange jackets,a heating fluid such as steam or hot water may be circulated through anannulus between the heat apparatus 371 and riser 320 and/or between theheat apparatus 372 and the downcomer 340. The circulation of the heatingfluid can add heat to the polymerization zone 321 and/or polymerizationzone 341 via heat transfer through the reactor wall of the MZCR 300. Theheating fluid may be circulated to a heating system configured to reheatthe heating fluid before returning to the annular region in a heatingcycle. When embodied as an electric heater, the heat apparatus 371and/or the heat apparatus 372 can be appropriately connected to anelectrical power supply that supplies power to raise the temperature ofelectrical heating elements. The heated heating elements can add heat tothe polymerization zone 321 and/or polymerization zone 341 via heattransfer through the reactor wall of the MZCR 300.

During operation of the MZCR 300 at polymerization conditions, the heatapparatus 371 and/or the heat apparatus 372 apparatus can be configuredto remove excess heat generated by the exothermic polymerizationreactions. When embodied as heat exchange jackets, a cooling fluid maybe circulated through the annulus between the heat apparatus 371 andriser 320 and/or between the heat apparatus 372 and the downcomer 340.The circulation of the cooling fluid can remove heat from thepolymerization zone 321 and/or polymerization zone 341 via heat transferthrough the reactor wall of the MZCR 300. The cooling fluid may becirculated to a cooling system configured to cool the cooling fluidbefore returning to the annular region in a cooling cycle.

In an aspect, the heat apparatus 371 may only cover a portion of theriser 320 and other portions of the riser 320 may not be subject to heattransfer. Likewise, the heat apparatus 372 may only cover a portion ofthe downcomer 340 and other portions of the downcomer 340 may not besubject to heat transfer. In further aspects, about 10% to about 100%;alternatively, about 20% to about 100%; alternatively, about 30% toabout 100%; alternatively, about 40% to about 100%; alternatively, about50% to about 100%; alternatively, about 60% to about 100%;alternatively, about 70% to about 100%; alternatively, about 70% toabout 100%; alternatively, about 80% to about 100%; alternatively, about90% to about 100% of the outer surface of the riser 320 may be subjectto heat exchange via the heat transfer apparatus 371. In furtheraspects, about 10% to about 100%; alternatively, about 20% to about100%; alternatively, about 30% to about 100%; alternatively, about 40%to about 100%; alternatively, about 50% to about 100%; alternatively,about 60% to about 100%; alternatively, about 70% to about 100%;alternatively, about 70% to about 100%; alternatively, about 80% toabout 100%; alternatively, about 90% to about 100% of the outer surfaceof the downcomer 340 may be subject to heat exchange via the heattransfer apparatus 372.

FIG. 3 also illustrates that the MZCR 300 can include a thermowell 374.The thermowell 374 is shown on the lower conduit 310; however, it iscontemplated than any number of thermowells can additionally oralternatively be included in the lower conduit 310, riser 320, upperconduit 330, separator 350, downcomer 340, elbow connector 302, elbowconnector 304, elbow connector 306, or a combination thereof. Atemperature sensing element, such as a thermocouple or a resistancetemperature detector (RTD) can be housed in each thermowell 374 andconfigured to sense a temperature at the location in the MZCR 300 atwhich the temperature sensing element is placed. Each temperaturesensing element can be appropriately connected to a process controlsystem or processes monitoring system for reading and/or control of theMZCR 300. The multiple sensed temperature values can be assembled into atemperature profile for any portion or the whole MZCR 300.

FIG. 3 additionally illustrates that the MZCR 300 can include a gasdensity meter 373. The gas density meter 373 can be configured tomeasure a density of the reaction mixture at the point where the gasdensity meter 373 is located. In FIG. 3, the gas density meter 373 islocated in the riser 320 and thus measures the gas density of the riserreaction mixture. Gas can flow into the gas density meter 373 via sampleconduit 373 a. Additionally or alternatively, it is contemplated thatthe gas density meter 373 can be located in other parts of the MZCR 300,e.g., i) one or more meters in the lower conduit 310 to measure the gasdensity of the downcomer product mixture along with any added recycledcomponents, ii) one or more meters in the upper conduit 330 to measurethe gas density of the riser product mixture, and iii) one or moremeters in the downcomer 340 to measure the gas density in the downcomer340. A commercial embodiment of the gas density meter 373 is an EMERSON®Micro Motion Gas Density Meter based on Coriolis effect. Other suitablegas density meters include on magnetic flow meters or thermodynamic flowmeters.

FIG. 4 illustrates the MZCR 300 having various additional aspects thatcan be utilized in FIG. 1 and/or FIG. 2 and with any combination ofaspects shown in FIG. 3. Feed lines 323, 324, and 325 are shown withdashed lines to indicate the optional use of these lines, since it isintended that the aspects and embodiments of the MZCR 300 shown in FIG.4 can be implemented in the MCZR 300 shown in FIG. 1 and/or FIG. 2.

FIG. 4 shows that the product discharge conduit 370 can be connected tothe downcomer 340 such that an angle of the product discharge conduit370 with respect to horizontal is in a range of −60° to 60°;alternatively, −45° to 45°; alternatively, −35° to 35°; alternatively,−25° to 25°; alternatively, 0° to 45°; alternatively, in a range of 10°to 35°; alternatively, in a range of 20° to 25°. For example, the angleof the product discharge conduit 370 with respect to horizontal can be−60°, −59°, −58°, −57°, −56°, −55°, −57°, −56°, −55°, −54°, −53°, −52°,−51°, −50°, −49°, −48°, −47°, −46°, −45°, −44°, −43°, −42°, −41°, −40°,−39°, −38°, −37°, −36°, −35°, −34°, −33°, −32°, −31°, −30°, −29°, −28°,−27°, −26°, −25°, −24°, −23°, −22°, −21°, −20°, −19°, −18°, −17°, −16°,−15°, −14°, −13°, −12°, −11°, −10°, −9°, −8°, −7°, −6°, −5°, −4°, −3°,−2°, −1°, 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°,14°, 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°,28°, 29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°,42°, 43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°,56°, 57°, 58°, 59°, or 60°. In an additional or alternative aspect, theproduct discharge conduit 370 can be connected to the downcomer 340 suchthat an angle of the product discharge conduit 370 with respect to alongitudinal axis of the downcomer 340 is in a range of 45° to 90°;alternatively, in a range of 55° to 80°; alternatively, in a range of65° to 70°. For example, the angle of the product discharge conduit 370with respect to the longitudinal axis of the downcomer 340 can be 45°,46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°, 59°,60°, 61°, 62°, 63°, 64°, 65°, 66°, 67°, 68°, 69°, 70°, 71°, 72°, 73°,74°, 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84°, 85°, 86°, 87°,88°, 89°, or 90°.

FIG. 4 also shows that a sample analyzer 377 configured to: i) analyze asample of the a reaction mixture at one or more locations in the MZCR300, ii) determine a concentration of gas, liquid, or solid in thereaction mixture, and iii) determine a concentration of monomer,comonomer, diluent, hydrogen, inert component, or polymer in thereaction mixture. The reaction mixture analyzed by the sample analyzer377 can be the reaction mixture from the lower conduit 310 (e.g., thedowncomer product mixture and any added recycled components), thereaction mixture from the riser 320 (e.g., the riser reaction mixture),the reaction mixture from the upper conduit 330 (e.g., the riser productmixture), or the reaction mixture from the downcomer 340 (e.g., thedowncomer reaction mixture). In an aspect, the sample analyzer 377 canbe configured to i) analyze a sample of the reaction mixture of theriser 320 and/or the reaction mixture of the downcomer 340 at one ormore locations in the MZCR 300, ii) determine a concentration of gas,liquid, or solid in the reaction mixture of the riser 320 and/or thereaction mixture of the downcomer 340, and iii) determine aconcentration of monomer, comonomer, diluent, hydrogen, inert component,or polymer in the reaction mixture of the riser 320 and/or the reactionmixture of the downcomer 340. In aspects, multiple sample analyzerssimilar to sample analyzer 377 can be included at various locations onthe MZCR 300. In additional or other aspect, one or more sampleanalyzers can be included on the product discharge conduit 110 and/orproduct discharge conduit 370. The sample analyzer 377 can include a gaschromatograph (GC) configured to determine the concentration of thegases sampled via a conduit 377 a that is connected to the interior ofthe MZCR 300. The analysis method can be Raman analysis, for example.The sample analyzer 377 can be configured to analyze a sample at a setfrequency of time, i.e., at designated periods of time (e.g., every 1,5, 10, 15, 20, 30, or 60 minutes). A commercially available sampleanalyzer 377 is a THERMO FISHER SCIENTIFIC® Raman gas analyzer or othercommercially available infrared spectrometer.

FIG. 4 also shows a level controller 378 configured to control a levelof polyolefin product in the separator 350 of the MZCR 300. The levelcontroller 378 can be coupled to the separator 350 and configured suchthat the polyolefin product has a residence time in an range of fromabout 1 to about 30 minutes; alternatively, from about 1 to about 5minutes; alternatively, from about 5 to about 10 minutes; alternatively,from about 10 to about 30 minutes in the separator 350.

The level controller 378 can be embodied as a valve, a level sensor, anda computer device connected to both the valve and the level sensor.

The valve of the level controller 378 can be positioned at the bottom ofthe separator 350 and configured to operate between an open position anda closed position. In the open position, the valve allows polyolefinproduct to pass from the separator 350 to the liquid barrier 360 of thedowncomer 350. In the closed position, the valve prevents the polyolefinproduct from passing from the separator 350 into the liquid barrier 360.In operation, the valve of the level controller 380 can actuate betweenthe open and closed positions in order to control the amount ofpolyolefin product that passes from the separator 350 into the liquidbarrier 360. The valve can be electrically and/or pneumaticallyconnected to the computer device of the level controller 378 such thatactuation of the valve can be accomplished.

The level sensor of the level controller 378 can be configured to sensean amount (e.g., the level) of the polyolefin product in the separator350. The level sensor can be a pressure sensor or pressure transducerpositioned on the bottom of the separator 350 that measures a pressureor weight of the polyolefin product that accumulates in the bottom ofthe separator 350. Alternatively, the level sensor can be anelectro-optical sensor positioned anywhere on the separator 350 so as tomeasure the presence of the polyolefin product at a threshold level inthe separator 350. For example, an electro-optical sensor can be locatedon the wall of the separator 350 and configured to measure a disruptionin light caused by the presence of the polyolefin product in front ofthe sensor, i.e., the amount of polyolefin product is at a thresholdheight in the in the separator 350 such that actuation of the valve intothe open position is made by the level controller 378. Regardless howthe level sensor is embodied, the level controller 378 can be configuredto actuate the valve between the open position and the closed positionin response to input from the level sensor (e.g., in the form of apressure sensor, transducer, or electro-optical sensor). The levelsensor can be electrically and/or pneumatically connected to thecomputer device of the level controller 378 such that measurement of thelevel of the polyolefin product in the separator 350 can be made.

The computer device of the level controller 378 can be speciallyconfigured with an input port that connects to the level sensor and anoutput port than connects to the valve. The computer device of the levelcontroller 378 can be programmed to receive signals (e.g., electricaland/or pneumatic signals) from the level sensor, to analyze the receivedsignals based on a control algorithm, and to send signals (e.g.,electrical and/or pneumatic signals) to the valve of the levelcontroller 378 that cause the valve either to actuate to the openposition or to the closed position.

FIG. 4 shows additionally that an anti-static agent feed line 346 can beconfigured to inject an anti-static agent into the MZCR 300. While FIG.4 shows the feed line 346 fluidly connected near the top portion 348 ofthe downcomer 340, it is contemplated that the feed line 346 can beconnected anywhere on the MZCR 300. Additionally, it is contemplatedthat the feed line 346 can comprise more than one line configured toinject the anti-static agent at various locations along the downcomer340 or anywhere along the MZCR 300. In an embodiment, the feed line 346can be configured to inject a mixture comprising an anti-static agentand a carrier fluid. In an aspect of such embodiment, the concentrationof the anti-static agent in feed line 346 (or each feed line when morethan one is used) is in an range of from about 1 ppm to about 50 ppm;alternatively, from about 1 ppm to about 5 ppm; alternatively, about 5ppm to about 10 ppm; alternatively, about 10 ppm to about 50 ppm, basedon weight of the carrier fluid in the feed line 346. In an additional oralternative aspect of such embodiment, the concentration of theanti-static agent in feed line 346 (or each feed line when more than oneis used) is about 1 ppm to about 50 ppm; alternatively, from about 1 ppmto about 5 ppm; alternatively, about 5 ppm to about 10 ppm;alternatively, about 10 ppm to about 50 ppm, based on weight of thecarrier fluid in the MZCR 300. In an aspect, the anti-static agent canbe STADIS® 425, STADIS® 450, STATSAFE™ 2000, STATSAFE™ 3000, STATSAFE™6000, ammonium salts, or other commercially available anti-static agent.

FIG. 4 also shows that a reactor deactivator feed line 347 can beincluded on the MZCR 300. The feed line 347 is shown as connecting tothe downcomer 340; however, it is contemplated that the reactordeactivator feed line 347 can be placed anywhere on the MZCR 300. It isalso contemplated that the MZCR 300 can have multiple reactordeactivator feed lines 347. The reactor deactivator feed line 347 isuseful on the MZCR 300 when the multiple zone configuration of FIG. 1 isutilized, since the MZCR 300 is the last of the two reactors 100 and300. It is contemplated that a deactivator feed line can additionally oralternatively be included on the first reactor 100 when the multiplezone configuration of FIG. 2 is utilized.

In and aspect, the reactor deactivation agent introduced via feed line347 can be carbon monoxide or an alcohol. In an aspect, the reactordeactivation agent is not water, so as to prevent the internals of theMZCR 300 (or first reactor 100) from rusting.

A reactor deactivation agent is useful when the MZCR 300 (and/or thefirst reactor 100) must be shut down. The reactor deactivation agent canlead to a stoppage of the polymerization reactions, which then canenable stoppage of the reactors. In another aspect, the reactordeactivation agent is useful to partially reduce, or moderate, thepolymerization reactions in the MZCR 300 (and/or the first reactor 100).Moderation enables slowing the polymerization reaction enough that theMZCR 300 and/or the first reactor 100 can be stopped for about 20 toabout 60 minutes and then restarted, for example, to start a newpolyolefin product run. The amount of reactor deactivation agentrequired for a total stoppage is greater than the amount required formoderation.

FIGS. 5A and 5B illustrate cross-sectional views of embodiments of aneductor 375, and FIG. 5C illustrates a perspective view of a standpipe390. The eductor 375 and/or standpipe 390 can be used with the MZCR 300in FIG. 1 and/or FIG. 2, along with any combination of aspects shown inFIGS. 3 and 4. The configuration of the eductor 375 differs in variousaspects between FIG. 5A and FIG. 5B, as is discussed below.

The eductor 375 of FIG. 5A is configured to increase a velocity of thefluids entering the eductor 375 such that the velocity of the fluidsexiting the eductor 375 is higher than the velocity of the fluidsentering the eductor 375. The design of the eductor 375 shown in FIG. 5Ais intended to be exemplary and non-limiting, and other designs thatfunction to increase the velocity of fluids that enter the eductor 375are contemplated. The eductor 375 has two inlets 375 a and 375 b, andone outlet 375 c. The inlet 375 b and outlet 375 c generally share thesame longitudinal axis. The longitudinal axis of the inlet 375 b isgenerally at an angle, for example 15° to 90°, relative to thelongitudinal axis of the inlet 375 b and outlet 375 c.

Referring still to the eductor 375 in FIG. 5A, a reaction mixturecontaining polyolefin particles can enter the eductor 375 at inlet 375a. A motive fluid, for example, of recycled monomer/comonomer fromconduit 502 or 503 in FIG. 1 or FIG. 2, can enter the eductor 375 atinlet 375 b. The inlet 375 b of the eductor 375 in FIG. 5A can beconfigured such that a portion 375 d of the inlet 375 b extends into theinterior of the eductor 375 and is contoured in the shape of a nozzlesuch that the motive fluid is forced to flow at a higher velocity in thedirection of arrow C. The flow of the motive fluid out of thenozzle-shaped portion 375 d creates suction at inlet 375 a that aids indrawing the reaction mixture into the eductor 375. The reaction mixturemixes with the motive fluid in the interior of the eductor 375, and themixture flows in the direction of arrow C and out of the outlet 375 c ofthe eductor 375 at an exit velocity that is higher than either or bothof the inlet velocity of the motive fluid and the inlet velocity of thereaction mixture. In an aspect, a portion 375 e of the body of theeductor 375 in FIG. 5A can be tapered such that the inner diameter ofthe portion 375 e of the eductor 375 decreases in the direction of arrowC. In another aspect, a portion 375 f of the body of the eductor 375 inFIG. 5A can be tapered such that the inner diameter of the portion 375 fof the eductor 375 increases in the direction of arrow C. In anotheraspect, the motive fluid can be pressurized before entering the eductor375, for example, by a pump or compressor positioned upstream of theeductor 375. In a further aspect, the eductor 375 of FIG. 5A can beoriented in the MZCR 300 such that the direction of flow indicated byarrow C is horizontal, vertical, or at an angle with respect tohorizontal.

The eductor 375 of FIG. 5B is configured to increase a velocity of thefluids entering the eductor 375 such that the velocity of the fluidsexiting the eductor 375 is higher than the velocity of the fluidsentering the eductor 375. The design of the eductor 375 shown in FIG. 5Bis intended to be exemplary and non-limiting, and other designs thatfunction to increase the velocity of fluids that enter the eductor 375are contemplated. The eductor 375 has two inlets 375 a and 375 b, andone outlet 375 c. The inlet 375 b and outlet 375 c generally share thesame longitudinal axis. The longitudinal axis of the inlet 375 b isgenerally at an angle, for example perpendicular, relative to thelongitudinal axis of the inlet 375 b and outlet 375 c.

Referring still to the eductor 375 in FIG. 5B, a motive fluid, forexample, of recycled monomer/comonomer from conduit 502 or 503 in FIG. 1or FIG. 2, can enter the eductor 375 at inlet 375 a. A reaction mixturecontaining polyolefin particles can enter the eductor 375 at inlet 375b. This is the opposite configuration of the eductor 375 in FIG. 5A,where the reaction mixture enters inlet 375 a and the motive fluidenters inlet 375 b.

The inlet 375 a of the eductor 375 in FIG. 5B can be configured suchthat a portion 375 g of the inlet 375 a extends into the interior of theeductor 375. The portion 375 g bends within the interior of the eductor375 such that the end 375 h of the inlet 375 a has a longitudinal axisthat is parallel to or the same as the longitudinal axis of the inlet375 b and outlet 375 c. The end 375 h can also be contoured in the shapeof a nozzle such that the motive fluid is forced to flow at a highervelocity in the direction of arrow C. The flow of the motive fluid outof the nozzle-shaped end 375 h creates suction at inlet 375 b that aidsin drawing the reaction mixture into the eductor 375. The reactionmixture mixes with the motive fluid in the interior of the eductor 375,and the mixture flows in the direction of arrow C and out of the outlet375 c of the eductor 375 at an exit velocity that is higher than eitheror both of the inlet velocity of the motive fluid and the inlet velocityof the reaction mixture. In an aspect, a portion 375 e of the eductor375 can be tapered such that the inner diameter of the portion 375 e ofthe eductor 375 decreases in the direction of arrow C. In anotheraspect, the motive fluid can be pressurized before entering the eductor375, for example, by a pump or compressor positioned upstream of theeductor 375. In further aspect, the eductor 375 of FIG. 5B can beoriented in the MZCR 300 such that the direction of flow indicated byarrow C is horizontal, vertical, or at an angle with respect tohorizontal.

FIG. 5C illustrates a perspective view of a standpipe 390. The standpipe390 is generally a length of pipe having a wall thickness adequate forhigh pressure fluid. That is, the wall 391 of the standpipe 390 can havea thickness that is greater than the wall of the conduits which form theMZCR 300, due to the higher pressure of fluid that passes through thechannel 392 of the standpipe 390. In aspects, the diameter of thestandpipe 390 can be from about 2 to about 48 inches (about 5 to about122 cm); alternatively, from about 12 to about 24 inches (about 30.5 toabout 61 cm); alternatively, from about 6 to about 12 inches (about 15.2to about 30.5 cm). In an aspect, a diameter of the standpipe 390 can beless than a diameter (e.g., inner diameter and/or outer diameter) of thelower conduit 310 of the MZCR 300. Generally, the standpipe 390 can havea uniform diameter along a length thereof such that end 390 a of thestandpipe 390 has an outer diameter and inner diameter that is equal tothe outer diameter and inner diameter of the opposite end 390 b. Thethickness of the wall 391 of the standpipe 390 can be, for example, fromabout 0.1, 0.2, 0.3, 0.4, or 0.5 inches (about 0.254, 0.508, 0.762,1.02, or 1.27 cm) to about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5 inches(about 2.54, 3.81, 5.08, 6.35, 7.62, 8.89, 10.2, 11.4, or 12.7 cm). In afurther aspect, the length of the standpipe 390 can be any lengthsuitable for delivering the high pressure fluid to the MZCR 300, forexample, 0.328, 1.64, 3.28, 4.92, 6.56, 8.20, 9.84, 11.5, 13.1, 14.8, or16.4 ft (0.1, 0.5, 1, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, or 5.0 meters).In yet a further aspect, it is contemplated that the standpipe 390 caninclude bends, elbow connectors, straight portions, or combinationsthereof. Further, it is contemplated that the standpipe 390 can beformed from multiple piping segments, for example, to traverse thedistance between a compressor and the MZCR 300 in the plant.

FIGS. 5D to 5J illustrate embodiments of the MZCR 300 that utilize theeductor 375 and/or standpipe 390 in various configurations and aspects.The configurations shown in FIGS. 5D to 5J can be utilized in the MZCR300 of FIG. 1 and/or FIG. 2, along with any combination of aspects shownin FIGS. 3 and 4. Feed lines 323, 324, and 325 in each of FIGS. 5D to 5Jare shown with dashed lines to indicate the optional use of these lines,since it is intended that the aspects and embodiments of the MZCR 300shown in FIGS. 5D to 5J can be implemented in the MCZR 300 shown in FIG.1 and/or FIG. 2.

In FIG. 5D, the eductor 375 of FIG. 5A is placed in the MZCR 300 suchthat inlet 375 a is fluidly connected to the bottom portion 349 of thedowncomer 340 and such that outlet 375 c is fluidly connected to the end311 of the lower conduit 310. The bottom portion 349 of the downcomer340 can be tapered in a conical manner so as to facilitate flow of thedowncomer product mixture into the inlet 375 a of the eductor 375. Inlet375 b of the eductor 375 is fluidly connected to conduit 502 such thatunreacted olefin monomer, unreacted olefin comonomer, diluent, or acombination thereof enters the eductor 375.

The flow of the unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof out of the nozzle-shaped portion 375 dcreates suction at inlet 375 a that aids in drawing the downcomerproduct mixture into the eductor 375. The downcomer product mixturemixes with the unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof in the interior of the eductor 375 toform an eductor reaction mixture, and the eductor reaction mixture flowsin the direction of arrow C and out of the outlet 375 c of the eductor375 and into the lower conduit 310. The eductor 375 helps the eductorreaction mixture exit the eductor 375 at an exit velocity that is i)greater than a saltation velocity of the eductor reaction mixture and upto about 30.48 m/s (100 ft/sec), or ii) greater than 110% of thesaltation velocity of the eductor reaction mixture. The exit velocity ofthe eductor reaction mixture moves the mixture through the lower conduit310 in the direction of arrow A, where the eductor reaction mixturemixes with additional unreacted olefin monomer, unreacted olefincomonomer, diluent, or a combination thereof provided by conduit 503 toform a lower conduit reaction mixture. The lower conduit reactionmixture mixes with feed components provided by feed lines 322, 323, 324,and/or 325 to form the riser reaction mixture. For the polymerization ofFIG. 1, the first polyolefin received from conduit 202 can additionallymix with the eductor reaction mixture flowing in the lower conduit 310such that the first polyolefin and the eductor reaction mixture flow inthe lower conduit reaction mixture.

The angle between the longitudinal axis of the inlet 375 a and inlet 375b in FIG. 5D is perpendicular, and the direction of flow of arrow C ishorizontal.

The eductor 375 of FIG. 5D replaces the elbow connector 306 shown inFIG. 1 and FIG. 2.

In FIG. 5E, the eductor 375 of FIG. 5A is placed in the MZCR 300 suchthat inlet 375 a is fluidly connected to the end 312 of the lowerconduit 310 and such that outlet 375 c is fluidly connected to thebottom portion 329 of the riser 320. The bottom portion 329 of the riser320 can be tapered in a conical manner so as to facilitate connection tothe outlet 375 c of the eductor 375. Inlet 375 b of the eductor 375 isfluidly connected to conduit 503 such that unreacted olefin monomer,unreacted olefin comonomer, diluent, or a combination thereof enters theeductor 375.

The flow of the unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof out of the nozzle-shaped portion 375 dcreates suction at inlet 375 a that aids in drawing the lower conduitreaction mixture (e.g., containing the downcomer product mixture and anyrecycled components added via conduit 502) from the lower conduit 310into the eductor 375. The lower conduit reaction mixture mixes with theadditional unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof in the interior of the eductor 375 toform the eductor reaction mixture, and the eductor reaction mixtureflows in the direction of arrow C and out of the outlet 375 c of theeductor 375. The eductor reaction mixture exits the eductor 375 at anexit velocity that is i) greater than a saltation velocity of theeductor reaction mixture and up to about 30.48 m/s (100 ft/sec), or ii)greater than 110% of the saltation velocity of the eductor reactionmixture. The eductor reaction mixture mixes with any added feedcomponents via conduits 322, 323, 324, and/325 to form the riserreaction mixture. The exit velocity of the eductor reaction mixturehelps move the riser reaction mixture (which contains the eductorreaction mixture and any components added via conduits 322, 323, 324,and/or 325) through riser 320 in an upward direction. The momentum ofthe riser reaction mixture through the riser 320 helps move the riserproduct mixture through the upper conduit 330. For the polymerization ofFIG. 1, the first polyolefin received from conduit 202 can mix with thelower conduit reaction mixture flowing in the lower conduit 310 suchthat the first polyolefin and the lower conduit reaction mixture flowinto the eductor 375.

The angle between the longitudinal axis of the inlet 375 a and inlet 375b in FIG. 5E is perpendicular, and the direction of flow of arrow C isvertical.

It is contemplated that embodiments of the MZCR 300 can have an eductor375 placed as shown in FIG. 5D in combination with an eductor placed asshown in FIG. 5E.

The eductor 375 of FIG. 5E replaces the elbow connector 302 shown inFIG. 1 and FIG. 2.

In FIG. 5F, the eductor 375 of FIG. 5B is placed in the MZCR 300 suchthat inlet 375 b is fluidly connected to the end 311 of the lowerconduit 310 and such that outlet 375 c is fluidly connected to the end312 of the lower conduit 310. Inlet 375 a of the eductor 375 is fluidlyconnected to conduit 502 such that unreacted olefin monomer, unreactedolefin comonomer, diluent, or a combination thereof enters the eductor375 via the inlet 375 a.

The flow of the unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof out of the portion 375 g of the inlet375 a that extends into the interior of the eductor 375 creates suctionat inlet 375 b that aids in drawing the downcomer product mixture fromthe end 311 of the lower conduit 310 into the eductor 375. The downcomerproduct mixture mixes with the unreacted olefin monomer, unreactedolefin comonomer, diluent, or a combination thereof in the interior ofthe eductor 375 to form an eductor reaction mixture, and the eductorreaction mixture flows in the direction of arrow C and out of the outlet375 c of the eductor 375 and into the end 312 of the lower conduit 310.The eductor reaction mixture flows out of the eductor 375 at an exitvelocity that is i) greater than a saltation velocity of the eductorreaction mixture and up to about 30.48 m/s (100 ft/sec), or ii) greaterthan 110% of the saltation velocity of the eductor reaction mixture. Theexit velocity of the eductor reaction mixture moves the mixture throughthe lower conduit 310 and into the riser 320 (e.g., via the elbowconnector 302). The eductor reaction mixture can combine with theadditional unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof provided by conduit 503, forming alower conduit reaction mixture, and the lower conduit reaction mixturemixes with any feed components from lines 322, 323, 324, and/or 325 toform the riser reaction mixture. The riser reaction mixture movesthrough the riser 320 in an upward direction. The momentum of the riserreaction mixture through the riser 320 moves the riser product mixturethrough the upper conduit 330. For the polymerization of FIG. 1, thefirst polyolefin received from conduit 202 can mix with the eductorreaction mixture flowing in the lower conduit 310 such that the firstpolyolefin and the eductor reaction mixture flow in the lower conduitreaction mixture into the eductor 375.

The angle between the longitudinal axis of the inlet 375 a and inlet 375b in FIG. 5F is less than 90°, and the direction of flow of arrow C ishorizontal.

It is contemplated that embodiments of the MZCR 300 can have the eductor375 as shown in FIG. 5F in combination with an eductor 375 placed asshown in FIG. 5D and/or with an eductor placed as shown in FIG. 5E.

In FIG. 5G, the eductor 375 of FIG. 5B is placed in the MZCR 300 suchthat inlet 375 b is fluidly connected to the bottom portion 349 of thedowncomer 340 and such that outlet 375 c is fluidly connected to the end311 of the lower conduit 310 (e.g., via the elbow connector 306). Inlet375 a of the eductor 375 is fluidly connected to conduit 502 such thatunreacted olefin monomer, unreacted olefin comonomer, diluent, or acombination thereof enters the eductor 375 via the inlet 375 a.

The flow of the unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof out of the portion 375 g of the inlet375 a that extends into the interior of the eductor 375 creates suctionat inlet 375 b that aids in drawing the downcomer product mixture fromthe downcomer 340 into the eductor 375. The downcomer product mixturemixes with the unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof in the interior of the eductor 375 tofor an eductor reaction mixture, and the eductor reaction mixture flowsin the direction of arrow C and out of the outlet 375 c of the eductor375 and into the end 311 of the lower conduit 310. The eductor reactionmixture exits the eductor 375 at an exit velocity that is i) greaterthan a saltation velocity of the eductor reaction mixture and up toabout 30.48 m/s (100 ft/sec), or ii) greater than 110% of the saltationvelocity of the eductor reaction mixture. The exit velocity helps tomove the educator reaction mixture through the lower conduit 310. Theeductor reaction mixture combines with the unreacted olefin monomer,unreacted olefin comonomer, diluent, or a combination thereof providedby conduit 503 to for the lower conduit reaction mixture. The lowerconduit reaction mixture mixes with feed components added be any of feedconduits 322, 323, 324, and/or 325 to form the riser reaction mixture.The riser reaction mixture moves through the riser 320 in an upwarddirection. The riser reaction mixture exits the riser 320 as the riserproduct mixture, and the riser product mixture flows through the upperconduit 330 to the separator 350. For the polymerization of FIG. 1, thefirst polyolefin received from conduit 202 can mix with the eductorreaction mixture flowing in the lower conduit 310.

The angle between the longitudinal axis of the inlet 375 a and inlet 375b in FIG. 5G is less than 90°, and the direction of flow of arrow C isvertical.

It is contemplated that embodiments of the MZCR 300 can have the eductor375 as shown in FIG. 5G in combination with an eductor 375 placed asshown in FIG. 5D, with an eductor 375 placed as shown in FIG. 5E, withan eductor 375 placed as shown in FIG. 5F, or a combination thereof.

In FIG. 5H, the eductor 375 of FIG. 5B is placed in the MZCR 300 suchthat inlet 375 b is fluidly connected to the end 312 of the lowerconduit 310 and such that outlet 375 c is fluidly connected to thebottom portion 329 of the riser 320 (e.g., via the elbow connector 302).Inlet 375 a of the eductor 375 is fluidly connected to conduit 503 suchthat unreacted olefin monomer, unreacted olefin comonomer, diluent, or acombination thereof enters the eductor 375 via the inlet 375 a.

The flow of the unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof out of the portion 375 g of the inlet375 a that extends into the interior of the eductor 375 creates suctionat inlet 375 b that aids in drawing the lower conduit reaction mixturefrom the lower conduit 310 into the eductor 375. The lower conduitreaction mixture received at inlet 375 b can contain i) the downcomerproduct mixture, ii) unreacted olefin monomer, unreacted olefincomonomer, diluent, or a combination thereof provided by conduit 502,and optionally iii) the first polyolefin delivered via conduit 202 (seethe polymerization in FIG. 1). The lower conduit reaction mixturereceived at inlet 375 b mixes with the unreacted olefin monomer,unreacted olefin comonomer, diluent, or a combination thereof providedby conduit 503 in the interior of the eductor 375 to for the eductorreaction mixture, and the eductor reaction mixture flows in thedirection of arrow C and out of the outlet 375 c of the eductor 375. Theeductor reaction mixture exits the eductor 375 at an exit velocity thatis i) greater than a saltation velocity of the eductor reaction mixtureand up to about 30.48 m/s (100 ft/sec), or ii) greater than 110% of thesaltation velocity of the eductor reaction mixture. The eductor reactionmixture mixes with any feed components provided by feed conduits 322,323, 324, and/or 325 to form the riser reaction mixture. The riserreaction mixture flows into the riser 320 and upward therethrough. Theriser reaction mixture exits the riser 320 as the riser product mixture.The exit velocity of the riser product mixture helps to move the riserproduct mixture through the upper conduit 330 to the separator 350.

The angle between the longitudinal axis of the inlet 375 a and inlet 375b in FIG. 5H is less than 90°, and the direction of flow of arrow C isvertical.

It is contemplated that embodiments of the MZCR 300 can have the eductor375 as shown in FIG. 5H in combination with an eductor 375 placed asshown in FIG. 5D, with an eductor 375 placed as shown in FIG. 5E, withan eductor 375 placed as shown in FIG. 5F, with an eductor 375 placed asshown in FIG. 5G, or a combination thereof.

In FIG. 5I, the standpipe 390 of FIG. 5C is fluidly connected to thelower conduit 310 (e.g., via the elbow connector 306). The outlet 390 bof the standpipe 390 connects to the MZCR 300. The inlet 390 a of thestandpipe 390 is fluidly connected to conduit 502, optionally via acompressor or pump 502 a. The compressor or pump 502 a is configured toincrease the pressure of the unreacted olefin monomer, unreacted olefincomonomer, diluent, or a combination thereof received from conduit 502.The inlet 390 a of the standpipe 390 can be directly connected to theoutlet of the compressor or pump 502 a so as to deliver the pressurizedcomponents to the interior of the MZCR 300 in the direction of arrow C.The pressured components enter the MZCR 300 and increase the velocity ofthe downcomer product mixture traveling out of the downcomer 340 andinto the lower conduit 310 such that the velocity of the downcomerproduct mixture reaches a velocity that is i) greater than a saltationvelocity of the downcomer product mixture and up to about 30.48 m/s (100ft/sec), or ii) greater than 110% of the saltation velocity of thedowncomer product mixture.

The direction of flow of arrow C in FIG. 5I is horizontal. It iscontemplated that embodiments of the MZCR 300 can have the standpipe 390as shown in FIG. 5I in combination with an eductor 375 placed as shownin FIG. 5D, with an eductor 375 placed as shown in FIG. 5E, with aneductor 375 placed as shown in FIG. 5F, with an eductor 375 placed asshown in FIG. 5G, with an eductor 375 placed as shown in FIG. 5H, or acombination thereof.

In FIG. 5J, the standpipe 390 of FIG. 5C is fluidly connected to thelower conduit 310 (e.g., via the elbow connector 302). The outlet 390 bof the standpipe 390 connects to the MZCR 300. The inlet 390 a of thestandpipe 390 is fluidly connected to conduit 503, optionally via acompressor or pump 503 a. The compressor or pump 503 a is configured toincrease the pressure of the unreacted olefin monomer, unreacted olefincomonomer, diluent, or a combination thereof received from conduit 502.The inlet 390 a of the standpipe 390 can be directly connected to theoutlet of the compressor or pump 502 a so as to deliver the pressurizedcomponents to the interior of the MZCR 300 in the direction of arrow C.The pressured components enter the MZCR 300 and increase the velocity ofthe lower conduit reaction mixture traveling out of the lower conduit310 such that a velocity of the lower conduit reaction mixture is i)greater than a saltation velocity of the lower conduit reaction mixtureand up to about 30.48 m/s (100 ft/sec), or ii) greater than 110% of thesaltation velocity of the lower conduit reaction mixture.

The direction of flow of arrow C in FIG. 5J is vertical. It iscontemplated that embodiments of the MZCR 300 can have the standpipe 390as shown in FIG. 5J in combination with an eductor 375 placed as shownin FIG. 5D, with an eductor 375 placed as shown in FIG. 5E, with aneductor 375 placed as shown in FIG. 5F, with an eductor 375 placed asshown in FIG. 5G, with an eductor 375 placed as shown in FIG. 5H, thestandpipe 390 as shown in FIG. 5I, or a combination thereof.

FIGS. 6A to 6C illustrate the MZCR 300 having various additional aspectsthat can be utilized in FIG. 1 and/or FIG. 2 and with any combination ofaspects shown in FIGS. 3, 4, and 5A to 5J. Feed lines 323, 324, and 325are shown with dashed lines to indicate the optional use of these lines,since it is intended that the aspects and embodiments of the MZCR 300shown in FIG. 6A can be implemented in the MCZR 300 shown in FIG. 1and/or FIG. 2.

In FIG. 6A, the MZCR 300 that includes a transition conduit 376. Thetransition conduit 376 can be fluidly connected to the end 311 of thelower conduit 310 and to the bottom portion 349 of the downcomer 340. Anangle of the lower conduit 310 with respect to horizontal can be lessthan about 90°; alternatively, greater than about 0° and less than about90°; alternatively, in a range of from about 0° to about 45°;alternatively, in a range of from about 45° to about 67.5°. An angle ofthe transition conduit 376 with respect to horizontal can be less thanabout 90°; alternatively, greater than about 0° and less than about 90°;alternatively, in a range of from about 0° to about 45°; alternatively,in a range of from about 45° to about 67.5°. In an aspect, the lowerconduit 330 and the transition conduit 376 are the same angle value withrespect to horizontal. A length of the transition conduit 376 can befrom about 0.305 m (1 ft) to about 4.57 m (15 ft); alternatively, about1.83 m (6 ft) to about 4.57 m (15 ft); alternatively, from about 0.305 m(1 ft) to about 1.5 m (5 ft); alternatively, about 1.5 m (5 ft) to about3.05 m (10 ft). FIG. 6A also shows that the transition conduit 376 canbe fluidly connected to the conduit 502. In an aspect, part of thetransition conduit 376 can be a flush and clean out chamber having alength of from about 0.305 m (1 ft) to about 1.5 m (5 ft);alternatively, about 1.5 m (5 ft) to about 3.05 m (10 ft).

FIG. 6A illustrates that the MZCR 300 can have elbow connector 302,elbow connector 304, and tee connector 307 (e.g., elbow connector 306 isreplaced by tee connector 307 due to the presence of the transitionconduit 376). As can be seen, elbow connector 302 can connect to thebottom portion 329 of the riser 320 and to the end 312 of the lowerconduit 310. More specifically, end 302 a of the elbow connector 302 canconnect to the bottom portion 329 of the riser 320, and end 302 b of theelbow connector 302 can connect to the end 312 of the lower conduit 310.Elbow connector 304 can connect to the top portion 328 of the riser 320and to the end 331 of the upper conduit 330. More specifically, end 304a of the elbow connector 304 can connect to the top portion 328 of theriser 320, and end 304 b of the elbow connector 304 can connect to theend 331 of the upper conduit 330. Tee connector 307 can connect to thebottom portion 349 of the downcomer 340, to the end 311 of the lowerconduit 310, and to an end 376 a of the transition conduit 376. Morespecifically, end 307 a of the tee connector 307 can connect to thebottom portion 349 of the downcomer 340, end 307 b of the tee connector307 can connect to the end 311 of the lower conduit 310, and end 307 cof the tee connector 307 can connect to the end 376 a of the transitionconduit 376. In an aspect, the a first angle θ_(A) formed between theend 307 a and the end 307 b of the tee connector 307 is equal to or lessthan about 90°, and an angle θ_(B) between the end 307 a and the end 307c is equal to or greater than 90°.

In FIG. 6B, an eductor 375 is used in combination with a transitionconduit 376 embodied as a standpipe 390. The eductor 375 is similar tothat illustrated in FIG. 5A, except the angle between the longitudinalaxis of the inlet 375 a and inlet 375 b in FIG. 6B is angle θ_(B) (angleθ_(B) is discussed for FIG. 6A). In an aspect, the angle θ_(B) in FIG.6B that is between the longitudinal axis of inlet 375 a and thelongitudinal axis of inlet 375 b is greater than 90° and less than 180°.

The eductor 375 is placed in the MZCR 300 such that inlet 375 a isfluidly connected to the bottom portion 349 of the downcomer 340 andsuch that outlet 375 c is fluidly connected to the end 311 of the lowerconduit 310. The bottom portion 349 of the downcomer 340 can be taperedin a conical manner so as to facilitate flow of the reaction mixtureinto the inlet 375 a of the eductor 375. The inlet 375 b of the eductor375 is fluidly connected to the outlet 390 b of the standpipe 390. Theinlet 390 a of the standpipe 390 can be fluidly connected to acompressor or pump 502 a.

The configuration and operation of the eductor 375 in FIG. 6B is similarto that described for FIG. 5D, except the recycled components arereceived at the inlet 375 b at a higher pressure due to use of thestandpipe 390 and compressor or pump 502 a. The downcomer productmixture received in the inlet 375 a from the downcomer 340 mixes withthe pressurized unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof in the interior of the eductor 375 toform a pressurized eductor reaction mixture, and the pressurized eductorreaction mixture flows in the direction of arrow C and out of the outlet375 c of the eductor 375 and into the lower conduit 310. The eductorreaction mixture exits the eductor 375 at an exit velocity that is i)greater than a saltation velocity of the eductor reaction mixture and upto about 30.48 m/s (100 ft/sec), or ii) greater than 110% of thesaltation velocity of the eductor reaction mixture. The exit velocity ofthe pressurized eductor reaction mixture (containing recycled componentsand the downcomer product mixture) exiting the eductor 375 is higherthan an inlet velocity of the reaction mixture at inlet 375 a and theinlet velocity of the recycled components at inlet 375 b.

The exit velocity helps to move the eductor reaction mixture through thelower conduit 310 in the direction of arrow A, where the eductorreaction mixture mixes with unreacted olefin monomer, unreacted olefincomonomer, diluent, or a combination thereof provided by conduit 503 toform the lower conduit reaction mixture. The lower conduit reactionmixture mixes with any feed components provided by conduits 322, 323,324, and/or 325 to form the riser reaction mixture. For thepolymerization of FIG. 1, the first polyolefin received from conduit 202can additionally mix with the eductor reaction mixture flowing in thelower conduit 310.

In FIG. 6B, the eductor 375 replaces the tee connector 307 shown in FIG.6A, and the transition conduit 376 of FIG. 6A is embodied as thestandpipe 390 in FIG. 6B.

In alternative aspect for FIG. 6B, it is contemplated that the inlet 375b of the eductor 375 can be fluidly connected to conduit 502 such thatunreacted olefin monomer, unreacted olefin comonomer, diluent, or acombination thereof enters the eductor 375 (i.e., in an embodiment,there is no standpipe 390) directly from the conduit 502. Alternativelystill, it is contemplated that the outlet 390 b of the standpipe 390 canbe fluidly connected to the tee connector 307 of the MZCR 300 shown inFIG. 6A such that unreacted olefin monomer, unreacted olefin comonomer,diluent, or a combination thereof enters the MZCR 300 directly from thestandpipe 300.

In FIG. 6C, a standpipe 390 of FIG. 5C is used in combination with thetransition conduit 376 having the configuration shown in FIG. 6A. Thestandpipe 390 is fluidly connected to the lower conduit 310 (e.g., viathe tee connector 307), and the outlet 390 b of the standpipe 390extends into the interior of the transition conduit 376. The inlet 390 aof the standpipe 390 is fluidly connected to conduit 502, optionally viaa compressor or pump 502 a. The compressor or pump 502 a is configuredto increase the pressure of the unreacted olefin monomer, unreactedolefin comonomer, diluent, or a combination thereof received fromconduit 502. While the inlet 390 a of the standpipe 390 is shown in FIG.6C as being inside the transition conduit 376, it is contemplated thatthe standpipe 390 can have portions that extend both inside and outsidethe transition conduit 376 such that the inlet 390 a is outside thetransition conduit 376 and the outlet 390 b of the standpipe 390 isinside the transition conduit 376.

The inlet 390 a of the standpipe 390 can be directly connected to theoutlet of the compressor or pump 502 a so as to deliver the pressurizedcomponents to the interior of the MZCR 300 in the direction of arrow C.The pressurized components enter the MZCR 300 and increase the velocityof the downcomer product mixture traveling out of the downcomer 340 andinto the lower conduit 310 such that a velocity of the downcomer productmixture is i) greater than a saltation velocity of the downcomer productmixture and up to about 30.48 m/s (100 ft/sec), or ii) greater than 110%of the saltation velocity of the downcomer product mixture.

FIG. 7 illustrates an isolated view of an elbow connector 700 having asmart elbow configuration. Any of elbow connectors 302, 304, and 306 canhave the smart elbow configuration shown in FIG. 7 for elbow connector700. That is, the elbow connector 700 can be the elbow connector 302connected to the bottom portion 329 of the riser 320 and to the oppositeend 312 of the lower conduit 310, the elbow connector 304 connected tothe top portion 328 of the riser 320 and to the end 331 of the upperconduit 330, or the elbow connector 306 connected to the bottom portion349 of the downcomer 340 and to the end 311 of the lower conduit 310.

In the smart elbow design, the elbow connector 700 can have a first tap701 on an outside radius 702 of the elbow connector 700 and a second tap703 on an inside radius 704 of the elbow connector 700. The taps 701 and702 can generally be holes or openings formed in the wall of the tubularstructure than forms the elbow connector 700 in order to fluidly connectthe interior space 705 of the elbow connector 700 with the differentialpressure meter 708 via sensing legs 706 and 707. The legs 706 and 707can be constructed of conduit such as pipe or tubes. The sensing leg 706on the outside radius 702 of the elbow connector 700 can be a highpressure leg, and sensing leg 707 on the inside radius 704 of the elbowconnector 700 can be a low pressure leg.

As fluid passes through the elbow connector 700, the pressure at theoutside radius 702 increases due to centrifugal force. A first pressureon the high pressure side of the elbow connector 700 is indicated bypressure in the sensing leg 706, and a second pressure on the lowpressure side of the elbow connector 700 is indicated by a pressure inthe sensing leg 707. The pressure in the sensing leg 706 is sensed by asensing element on the meter 708, and the pressure in the sensing leg707 is likewise sensed by a sensing element on the meter 708. The meter708 can be configured to calculate the flow rate of the reaction mixtureflowing through the elbow connector 700 based on the difference in thepressures sensed by the sensing elements of the differential pressuremeter 708. In aspects, the differential pressure meter 708 can include atransmitter for transmitting a signal indicative of the pressure sensedby and/or flow rate calculated by the meter 708, for example, to acomputer in a process control system and/or process monitoring system.

A flushing system can be included in the sensing legs 706 and 707 thatis configured to flush polyolefin particles from the legs 706 and 707,for example, using a component in the reaction mixture, such as theolefin monomer, olefin comonomer, diluent, or an inert gas. In additionto the flushing system, screens can be included in the hole or openingformed by each of the taps 701 and 703. The screen can be a wire meshmetal material (e.g., Johnson® type screens) configured to allow gaseouscomponents of the reaction mixture to pass while holding back solidpolyolefin particles from flowing into the legs 706 and 707.

Alternatively, a diaphragm can be placed in each hole or opening formedby the tap 701 and/or tap 703 to mitigate the plugging of the taps 701and/or 703 or plugging of the sensing legs 706 and/or 707 withpolyolefin particles. The diaphragm(s) may be a flexible and relativelythin piece of material, and generally circular in shape, such as a disc.The diaphragm can be constructed of a metal (e.g., stainless steel) orpolymer. In embodiments with diaphragms, sensing legs 706 and 707 can befilled with a fluid such as diluent, a hydraulic fluid (oil, mineraloil, etc.), or other fluid suitable for transmitting the pressure forcefor the length of the sensing legs 706 and 707 to the differentialpressure meter 708. The fluid in the legs 706 and 707 may be generallyhydraulically full. Therefore, as pressure is exerted on the diaphragm,the fluid inside the legs 706 and 707 then exerts pressure on thesensing elements of the differential pressure meter 708.

While FIG. 7 shows the taps 701 and 703 formed in the elbow connector700, it is contemplated that the taps 701 and 703, sensing legs 706 and707, and the differential pressure meter 708 can be locatedalternatively or additionally at other points in the MZCR reactor 300,such as the lower conduit 310, the riser 320, the upper conduit 330, thedowncomer 340, or the tee connector 307 (of FIG. 4).

FIG. 8A illustrates a side view of a cyclone separator 850, which can bea particular embodiment of the separator 350 shown in FIG. 1 and FIG. 2.FIG. 8B illustrates a top cross-sectional view of the cyclone separator850 of FIG. 8A, taken along sight line i-i. The following discussionabout the cyclone separator is with respect to both FIG. 8A and FIG. 8B.

As can be seen in FIGS. 8A and 8B, the cyclone separator 850 can be ahollow vessel having a conical shape. The top 854 of the cycloneseparator 850 has a diameter that is greater than a diameter of thebottom 852 of the separator 850. In an aspect, the cone angle θc of thecyclone separator 850 can be about 45° to about 80°; alternatively,about 50° to about 75°; alternatively, about 60° to about 65°;alternatively, about 45° to about 60°; alternatively, about 60° to about70°; alternatively, about 70° to about 80°.

The riser 320 is configured to produce a riser product mixture thatflows from the riser 320, through the upper conduit 330, and into thecyclone separator 850. Thus, cyclone separator 850 can be configured toreceive the riser product mixture (e.g., comprising solid particles ofpolyolefin particles and catalyst particles, and a gas mixture) at theseparator inlet 851 via the upper conduit 330 and to separate the riserproduct mixture such that the gas mixture exits via the outlet 855 atthe top 854 of the separator 850 (in line 353) and the solid particlesexit the cyclone separator 850 via the bottom 852 of the cycloneseparator 850 (e.g., into the liquid barrier).

The riser product mixture can enter the inner chamber 856 of the cycloneseparator 850 via the inlet 851 and near the top 854 of the cycloneseparator 850. A tangential velocity of the riser product mixtureentering the inner chamber 856 forces the solid particles to flow in adownward spiral path 858, due to inward radial acceleration of the solidparticles, and concurrently, due to gravitational force imparts downwardacceleration on the solid particles in the inner chamber 856 of thecyclone separator 850. The result is a downward movement of separatedsolid particles along the inner wall 857 in the downward spiral path858, while the gas mixture of the riser product mixture separates andmoves upward in the chamber 856 and exits via the outlet 855. In anaspect, the cyclone separator 850 can particularly be a high efficiencycyclone configured to separate 99 wt. % or more of the solid particleswhich have a size of from about 2 μm to about 10 μm from the gasmixture.

In another aspect, an angle θc with respect to horizontal of the end 332of the upper conduit 330 than connects to the cyclone separator 850 canbe about 0° to about 15°. In yet another aspect, a vertical distance hbetween the top 854 of the separator 850 and where the upper conduit 330connects to the separator 850 can be from about 0 m (0 ft) to about 6.10m (20 ft); alternatively, from about 0.305 m (1 ft) to about 3.048 m (10ft); alternatively, from about 0.305 m (1 ft) to about 1.52 m (5 ft).

In an aspect, cyclone separator 850 is a tangential flow cyclone, andinlet 851 is a tangential inlet. The tangential inlet 851 can have anentrance angle θ_(E) of about 0° to about 15°; alternatively, about 7°to about 11°, with respect to a tangent of the cyclone separator 850.Configuring the cyclone separator 850 as a tangential flow cycloneseparator entails that the inlet 851 is a tangential inlet. Thetangential inlet 351 can guide the riser product mixture entering thecyclone separator 850 toward the inner wall 857 to promote separation ofthe solid particles from the gas mixture in cyclone fashion as describedabove.

In another aspect, the tangential entrance velocity of the riser productmixture into the cyclone separator 850 can be from about 15.24 m/s (50ft/sec) to about 30.48 m/s (100 ft/sec); alternatively, about 18.29 m/s(60 ft/sec) to about 27.43 m/s (90 ft/sec); alternatively, about 21.34m/s (70 ft/sec) to about 24.39 m/s (80 ft/sec).

FIG. 9 illustrates an embodiment of the product separation system 400depicted in FIG. 1 and FIG. 2. As can be seen, the product separationsystem 400 can be configured to separate the a product mixturecontaining the multimodal polyolefin received from the product dischargeconduit 370 (if referring to the embodiment in FIG. 1) or productdischarge conduit 110 (if referring to the embodiment in FIG. 2) intovarious streams, including a multimodal polyolefin conduit 401, anolefin monomer conduit 402, an olefin comonomer conduit 403, a diluentconduit 404, a heavies conduit 405, and a waste gas conduit 406. FIG. 9illustrates additional conduits that are present in the productseparation system 400, including side conduit 451 that can containolefin monomer, gaseous components that are lighter than the olefinmonomer, and optionally, diluent.

Equipment in the product separation system 400 can include one or moreof a take-off valve 410, a heater 420, a separation vessel 430, adegassing vessel 440, a heavies distillation column 450, a lightsdistillation column 460, and a polishing apparatus 470.

In FIG. 9, the take-off valve 410 can be configured to receive theproduct mixture from the product discharge conduit 370 and to controlthe flow of the product mixture therethrough. The take-off valve 410 canbe any type of control valve known in the art to be useful forcontrolling flow of the product mixture. Such valves include ballvalves, v-ball valves, plug valves, globe valves and angle valves. In anaspect, the take-off valve 410 can have a diameter when 100% open in arange of from about 1.27 cm (0.5 inches) to about 7.62 cm (3 inches). Inan aspect, the take-off valve 410 can have a flow channel diametergreater than the largest expected polymer particle size even when thevalve 410 is required to be only a small amount open (for example,20-25% open), which gives a wide control range for the range of opennessof the take-off valve 410 (e.g., 20-100% open). The take-off valve 410may be actuated by a signal from a controller configured to operate thetake-off valve 410 in a continuous or a discontinuous (e.g.,intermittently opened) manner. The controller may be configured to fullyclose and then fully open the take-off valve 410 at set intervals andfor a certain duration, to actuate the take-off valve 410 to apercentage of openness, e.g., 20-100% open.

The product mixture can flow from the take-off valve 410 in conduit 411to a heater 420. In an optional embodiment, one or more of a catalystpoison (also referred to as a catalyst deactivator) and a cocatalystpoison (also referred to as a cocatalyst deactivator) can be added tothe conduit 411 via conduit 412. In such an embodiment, the productmixture with catalyst/cocatalyst poison/deactivator can flow from thetake-off valve 410 in conduit 411 to the heater 420. It is contemplatedthat the poison and/or deactivator added via line 412 can be addedanywhere in or upstream of the heater 420. Examples of the catalystpoison and/or cocatalyst poison include water and any alcohol.

The heater 420 can be coupled to the product discharge conduit 370,either directly, or as depicted in FIG. 9, via take-off valve 410 andconduit 411. In FIG. 9, the end 421 of the heater 420 is connected tothe conduit 411. The heater 420 can be configured to receive the productmixture and to add heat to the product mixture as the product mixturepasses through the heater 420. An objective of the heater 420 is todischarge the multimodal polyolefin in the product mixture at atemperature i) of about 54.4° C. (130° F.) to about 104.4° C. (220° F.),or ii) below a melting point of the multimodal polyolefin.

The heater 420 can have any configuration according to any configurationrecognized in the art with the aid of this disclosure. For example,heater 420 can be an electric heater wrapped around portions of theconduit 411, a heat exchanger such as a shell and tube heat exchanger(e.g., where a heating medium is separated by structural elements whichtransfer heat to the product mixture flowing through the heater 420), aflashline heater (e.g., with heat added by steam into a jacket, byelectric heaters, or by both in alternating portions along the heater420), or combinations thereof. Flashline heater configurations arediscussed further in U.S. Pat. Nos. 8,597,582 and 8,883,940, each ofwhich is incorporated by reference in its entirety. In an aspect, theheater 420 can be configured as an open flow channel flashline heater,which is a jacketed pipe of a constant diameter that is heater withsteam injected in the jacket at end 421 and condensate collected fromthe jacket at end 422 of the heater 420. In the open flow channelconfiguration, the jacket can include a common collection system for thesteam that condenses to water in the jacket after transferring heat tothe product mixture that moves through the heater 420. The collectionsystem can comprise an open downward angle flow section configured tocollect the condensate.

The separation vessel 430 can be coupled to the end 422 of the heater420 either directly or, as shown in FIG. 9, via conduit 423. Theseparation vessel 430 is configured to separate the heated productmixture into a plurality of streams (e.g., conduit 431 and conduit 432)comprising vapor, a polymer product, or both vapor and polymer product.The vapor can include the gases separated from the multimodalpolyolefin, and the polymer product can include the multimodalpolyolefin. The separation vessel 430 can be embodied as a flash tankconfigured to provide a reduction in pressure of the product mixturesuch that olefin monomer, any optional olefin comonomer, diluent, andother components (e.g., nitrogen, hydrogen, oxygen, methane, ethane,propane, butane, isobutane, pentane, hexane, heavier hydrocarbons, orcombinations thereof) separate from the multimodal polyolefin so as toyield conduit 431 comprising one or more of these gaseous components. Tothe extent that any liquid is contained in the heated product mixture,the pressure reduction provided in the flash tank can flash the liquidinto the gas phase for flow in conduit 431.

The separation vessel 430 can be a hollow vessel having a cone-shapedbottom portion that directs the flow of the multimodal polyolefin toconduit 432. In an aspect, the separation vessel 430 can operate withouta pressure reduction, for example, when the product mixture contains gascomponents and the multimodal polyolefin and no or a minimal amount ofliquid, since a reduction in pressure is not needed for flashing aliquid component to a gas phase.

The multimodal polyolefin in conduit 432 can optionally flow to adegassing vessel 440 that can be configured to receive the polymerproduct (e.g., the multimodal polyolefin) from the separation vessel 430and to remove at least a portion of a hydrocarbon (e.g., olefin monomer,any optional olefin comonomer, diluent, ethane, or combinations thereof)entrained within the polymer product. Conduit 441 can provide an inertgas (e.g., nitrogen or an inert hydrocarbon such as ethane, propane,n-butane, or isobutane) to the degassing vessel 440. The degassingvessel 440 can be operated at appropriate conditions (e.g., temperature,pressure, inert gas flow rate) such that the inert gas flows through thecollection of polyolefin particles present in the degassing vessel 440,removes entrained hydrocarbon from the polyolefin particles, movesupwardly through the degassing vessel 440 with the removedhydrocarbon(s), and exits the degassing vessel 440 along with thepreviously entrained hydrocarbon in conduit 442. The degassed polymerproduct (e.g., multimodal polyolefin) can be recovered via conduit 401.The degassing vessel 440 can be configured for plug flow of polymerproduct from top to bottom. The residence time of polymer product in thedegassing vessel 440 can be at least 10 minutes, at least 30 minutes,about 1 hour, or from about 1 hour to about 6 hours. The operatingpressure of the degassing vessel 440 can be a vacuum pressure,atmospheric pressure, or greater than atmospheric pressure. In aparticular aspect, the pressure of the degassing vessel 400 can be apressure in the range of from about 0 psia to about 50 psia (about−0.101 MPaa to about 0.345 MPaa).

In an optional aspect, conduit 201 containing gaseous componentsrecovered from the product mixture of the first reactor 100 in FIG. 1 orthe product mixture of the MZCR 300 in FIG. 2 can be combined with thegaseous components in conduit 431 such that the vapor that flows inconduit 431 additionally contains said gaseous components from conduit201.

The gaseous components in the vapor in conduit 431 can flow to a monomerrecovery system 480. The monomer recovery system 480 can be configuredto recover one or more of the olefin monomer, the olefin comonomer, thediluent, and other gaseous components (e.g., nitrogen, oxygen, hydrogen,or combinations thereof) from the vapor in conduit 431.

The monomer recovery system 480 in FIG. 9 is described in the context ofrecovery of the olefin monomer, olefin comonomer, diluent, and othergaseous components from conduit 431 by recovering these components invarious streams to a desired purity via separation techniques such asdistillation, absorption, membrane separation, flash separation,compression, condensation, or combinations thereof. The exactconfiguration of the monomer recovery system 480 can depend on whicholefin monomer, which olefin comonomer, and which diluent are used inthe polymerizations in the first reactor 100 and the MZCR 300. Forexample, for polymerization of ethylene monomer and 1-hexene comonomerwith an isobutane diluent, the monomer recovery system 480 asillustrated in FIG. 9 can be utilized (as will be described in moredetail below). Alternatively, when the olefin comonomer is closer inmolecular weight to the olefin monomer (e.g., 1-butene or propylene isused as the comonomer instead of 1-hexene), a lights distillation columncan be utilized where ethylene and lighter gaseous components arerecovered from the top of the lights distillation column, isobutane isrecovered from the bottom of the distillation column, and 1-butene orpropylene can be recovered from the bottom and/or optionally from a sidedraw of the lights distillation column. In such as aspect, the ethyleneand lighter components can be separately recovered in a polishingapparatus (embodiments and aspects are described for polishing apparatus470 in FIG. 9). Alternatively, it is contemplated that the monomerrecovery system 480 can be embodied simply as a compressor or series ofcompressors that recycle the vapor in conduit 431 to one or both of thefirst reactor 100 and MZCR 300, such as is described in the monomerrecovery process in U.S. Pat. No. 5,376,742.

In the embodiment of the monomer recovery system 480 illustrated in FIG.9, the monomer recovery system 480 includes a heavies distillationcolumns 450, a lights distillation column 460, and polishing apparatus470.

The heavies distillation column 450 can be configured to separate atleast one gaseous component from the group of gaseous componentsreceived into the column 450 from conduit 431. The components in conduit431 can be introduced into the heavies distillation column 450 at apressure in a range of from about 0.101 MPa (14.7 psi) to about 3.64 MPa(527.9 psi), alternatively, from about 0.108 MPa (15.7 psi) to about2.40 MPa (348 psi), alternatively, from about 0.586 MPa (85 psi) toabout 2.00 MPa (290 psi).

The heavies distillation column 450 can be operated at conditions (e.g.,temperature, pressure, number of trays, reflux rate, heating rate, andother parameters for controlling the operation of a distillation column)suitable to recover heavy hydrocarbons in conduit 405, the olefincomonomer in conduit 403, and components lighter than the olefincomonomer in conduit 451. For example, the heavies distillation column450 can be operated at a temperature in a range of from about 15° C.(59° F.) to about 233° C. (451.4° F.), alternatively, from about 20° C.(68° F.) to about 200° C. (392° F.), alternatively, from about 20° C.(68° F.) to about 180° C. (356° F.), and/or a pressure in a range offrom about 0.101 MPa (14.7 psi) to about 3.64 MPa (527.9 psi),alternatively, from about 0.108 MPa (15.7 psi) to about 2.40 MPa (348psi), alternatively, from about 0.586 MPa (85 psi) to about 2.00 MPa(290 psi).

In an aspect, the heavy hydrocarbons in conduit 405 include hydrocarbonsheavier than the olefin comonomer (e.g., C₆₊ hydrocarbons), the olefincomonomer in conduit 403 is 1-hexene, and the components lighter thanthe olefin comonomer in conduit 451 can include nitrogen, hydrogen,oxygen, methane, ethane, ethylene, propane, propylene, butane, 1-butene,isobutane, pentane, pentene or combinations thereof. In an additionalaspect, the components in conduit 405 are in the liquid phase, thecomponents in conduit 403 are in the liquid phase, and the components inconduit 451 are in the gas phase.

Components lighter than the olefin monomer may be present in conduit 451in an amount of from about 80 wt. % to about 100 wt. % based on a totalweight of the components in conduit 451; alternatively, from about 90wt. % to about 99.999999 wt. %; alternatively, from about 99 wt. % toabout 99.9999 wt. %. Components including C₅ and heavier hydrocarbonsmay be present in the conduit 451 in an amount from 0 wt. % to about 20wt. % based on a total weight of the intermediate hydrocarbon stream;alternatively, from about 10 wt. % to about 0.000001 wt. %;alternatively, from about 1.0 wt. % to about 0.0001 wt. %.

Components including hexane and heavier hydrocarbons may be present inconduit 405 in an amount greater than about 85 wt. % based on a totalweight of the components in conduit 405; alternatively, greater thanabout 90 wt. %; alternatively, greater than about 95 wt. %. In anembodiment, the components in conduit 405 can be directed to additionalprocessing steps or processes, or alternatively they may be disposed of,as appropriate.

The components present in conduit 403 can include the olefin comonomerof 1-hexene. 1-hexene can be present in conduit in an amount of fromabout 20 wt. % to about 98 wt. % based on a total weight of thecomponents in conduit 403; alternatively from about 40 wt. % to about 95wt. %; alternatively, from about 50 wt. % to about 95 wt. %.

Either of conduits 403 and 405 can be routed so as to recycle thecomponents therein to the first reactor 100 and/or to the MZCR 300.

The lights distillation column 460 can be configured to separate atleast one gaseous component from the group of gaseous componentsreceived into the column 460 from conduit 451. The lights distillationcolumn 460 can be operated at conditions (e.g., temperature, pressure,number of trays, reflux rate, heating rate, and other parameters forcontrolling the operation of a distillation column) suitable to recoverolefin-free diluent in conduit 404, the diluent in conduit 461, and theolefin monomer combined with components lighter than the olefincomonomer in conduit 462. For example, the lights distillation column460 can be operated at a temperature in a range of from about 50° C.(122° F.) to about 20° C. (68° F.); alternatively, from about 40° C.(104° F.) to about 10° C. (50° F.); alternatively, from about 30° C.(86° F.) to about 5° C. (41° F.), and a pressure in a range of from0.101 MPa (14.7 psi) to about 3.64 MPa (527.9 psi), alternatively, fromabout 0.108 MPa (15.7 psi) to about 2.40 MPa (348 psi), alternatively,from about 0.586 MPa (85 psi) to about 2.00 MPa (290 psi).

In an aspect, the light components in conduit 462 include hydrocarbonslighter than the diluent, the components in conduit 461 can include thediluent and olefin monomer, and the components in conduit 404 caninclude the diluent. In an additional aspect, the components in conduit404 are in the liquid phase, the components in conduit 461 are in theliquid phase, and the components in conduit 462 are in the gas phase.

The components emitted from the lights distillation column 460 in lighthydrocarbon conduit 462 may comprise the olefin monomer (e.g., ethylene)and other light gases (e.g., ethane, methane, carbon dioxide, nitrogen,hydrogen, or combinations thereof). In an aspect, ethylene may bepresent in light hydrocarbon conduit 462 in an amount from about 50 wt.% to about 99 wt. % based on a total weight of components in the lighthydrocarbon conduit 462; alternatively, from about 60 wt. % to about 98wt. %; alternatively, from about 70 wt. % to about 95 wt. %.

The components emitted from the lights distillation column 460 inbottoms conduit 404 may comprise propylene, propane, butane, isobutane,pentane, or combinations thereof. In an aspect, the bottoms conduit maybe free of olefins (i.e., “olefin-free”), alternatively, substantiallyfree of olefins, alternatively, essentially free of olefins. Forexample, olefin(s) may be present in bottoms conduit 404 in an amountless than about 1.0 wt. % based on a total weight of the components inthe bottoms conduit 404; alternatively, less than about 0.5 wt. %;alternatively, less than about 0.1 wt. %. The diluent may be present inthe bottom conduit in an amount greater than about 99.0 wt. % based on atotal weight of the components in the bottoms conduit 404;alternatively, greater than about 99.5 wt. %; alternatively, greaterthan about 99.9 wt. %.

The components emitted from the lights distillation column 460 in sidedraw conduit 461 can include isobutane and ethylene. For example,isobutane can be present in the side conduit 461 in an amount of greaterthan about 85 wt. % based on a total weight of components in the conduit461; alternatively, greater than about 90 wt. %; alternatively, greaterthan about 95 wt. %. Ethylene can be present in the side conduit 461 inan amount of less than about 15 wt. % based on a total weight ofcomponents in the conduit 461; alternatively, less than about 10 wt. %;alternatively, less than about 5 wt. %.

Either of conduits 404 and 461 can be routed so as to recycle thecomponents therein to the first reactor 100 and/or to the MZCR 300.

The polishing apparatus 470 can be configured to receive the conduit 462and to separate the received gaseous components into olefin monomer inconduit 402 and waste gases in conduit 406. The polishing apparatus 470can utilize any technique for separating the olefin monomer from thewaste gases, for example, compression, distillation (e.g., utilizingcryogenic and/or vacuum conditions), absorption, membrane separation,condensation, or combinations thereof.

An example of the polishing apparatus 470 is found in U.S. Pat. No.9,598,514, which is incorporated by reference in its entirety. Inaspects, the polishing apparatus 470 can include an absorption reactorconfigured to selectively absorb the olefin monomer from among thecomponents in conduit 462. Non-limiting examples of suitable absorptionreactors and/or absorption reactor configurations include an absorption(distillation) tower, a pressure-swing absorption (PSA) configuration, asparger tank, an agitation reactor, one or more compressors, one or morerecycle pumps, or combinations thereof. The absorption reactor cancontain a liquid absorption solvent system configured to selectivelyabsorb the olefin monomer, and the components in conduit 462 can enterthe absorption reactor so that the components (in the gas phase) bubbleupwardly through the liquid absorption solvent system. The olefinmonomer can be absorbed in the liquid absorption solvent system untilsaturation with the olefin monomer is reached. In an aspect, the olefinmonomer can be liberated from the solvent by a reduction in pressure(e.g., pressure swing absorption) and/or by elevating the solventtemperature (e.g., the olefin monomer liberates as a gas from thesolvent at elevated temperature). In an alternative aspect, a solventcirculation system can be utilized in the polishing apparatus 470 tocirculate saturated liquid absorption solvent system to a regenerator ofthe polishing apparatus 470. The olefin monomer can be liberated fromthe solvent in the regenerator, and in such as aspect, the olefinmonomer can flow in conduit 402 from the regenerator of the polishingapparatus 470.

In further aspects, the absorption reactor of the polishing apparatus470 can include a packed bed or column configured to maintain smallerbubble sizes (e.g., of the gas components received from conduit 462),for example, so as to maintain a relatively large surface area ofcontact between the gas and the liquid solvent and to maintain anefficiency of mass transfer and/or absorption of the gas into theliquid. In aspects, the packing material of the packed bed or column caninclude a polymeric material, a metallic material, or combinationsthereof. It is contemplated that in the pressure swing absorptionconfiguration, the polishing apparatus 470 can include multipleabsorption reactors operating in parallel such that at least one reactorcan be taken off-line to liberate the olefin monomer from the liquidabsorption solvent system while at least another reactor in parallel canbe on-line to capture the olefin monomer received from conduit 462. Anexample of a suitable absorption reactor is illustrated in the GasProcessors Association, “Engineering Data Book” 10^(th) ed. at FIG.19-16, which is incorporated by reference in its entirety.

In aspects where the components in conduit 462 include ethylene as theolefin monomer and ethane is among the other gases, the absorptionsolvent system may be characterized as having a selectivity of ethyleneto ethane where ethylene and ethane are present at the same partialpressure of about 40:1 at about 96.5 kPa (14 psi); alternatively, about12:1 at about 138 kPa (20 psi); alternatively, about 6:1 at about 276kPa (40 psi); alternatively, about 3:1 at about 1.24 MPa (180 psi)partial pressure.

In aspects, the absorption reactor of the polishing apparatus 470 can beconfigured to operate in a temperature range of from about 4.4° C. (40°F.) to about 43.3° C. (110° F.); alternatively, from about 4.4° C. (40°F.) to about 15.6° C. (60° F.); alternatively, from about 7.2° C. (45°F.) to about 12.8° C. (55° F.); alternatively, from about 10° C. (50°F.) to about 12.8° C. (55° F.); alternatively about 10° C. (50° F.).

In aspects, the absorption reactor of the polishing apparatus 470 can beconfigured to operate in a pressure range of from about 34.5 kPag (5psig) to about 3.45 MPag (500 psig); alternatively, from about 0.345MPag (50 psig) to about 3.10 MPag (450 psig); alternatively, from about0.517 MPag (75 psig) to about 2.76 MPag (400 psig). In aspects thatinvolve ethylene as the olefin monomer recovered in conduit 402 of thepolishing apparatus 470, the absorption reactor can be configured toprovide or maintain a suitable partial pressure of ethylene in a rangeof from about 6.89 kPaa (1 psia) to about 2.76 MPaa (400 psia);alternatively, from about 0.207 MPaa (30 psia) to about 1.38 MPaa (200psia); alternatively, from about 0.276 MPaa (40 psia) to about 1.72 MPaa(250 psia); alternatively, from about 0.276 MPaa (40 psia) to about0.517 MPaa (75 psia); alternatively, from about 0.276 MPag (40 psig) toabout 0.414 MPag (60 psig); alternatively about 0.276 MPag (40 psig);alternatively, about 0.414 MPag (60 psig).

In aspects, the liquid absorption solvent system contains a solvent. Thesolvent can be an amine or an amine complex, an aromatic hydrocarbon, anolefin, or combinations thereof. Non-limiting examples of solvent aminesinclude pyridine, benzylamine, and aniline. For example, the amine maycomprise an aniline (phenylamine, aminobenzene); alternatively, anilinecombined with dimethylformamide (DMF), and in embodiments, aniline andN-methylpyrrolidone (NMP). In aspects where the solvent comprises anaromatic hydrocarbon, the aromatic hydrocarbon may comprise anunsubstituted or alkyl substituted aryl groups. The aromatic hydrocarbonmay be in the liquid phase under normal, ambient conditions. Suitablenon-limiting examples include toluene, xylene, and the like. In aspectswhere the solvent comprises an olefin, non-limiting examples includeolefins having 10 to 16 carbon atoms. For example, the olefinfunctioning as a solvent (which is not the olefin monomer from conduit462 being absorbed) can comprise propylene tetramer, dodecene,tetradecene, hexadecene, or combinations thereof. In aspects, thesolvent may be characterized as aprotic, that is, as not including adissociable hydrogen atom. Not intending to be bound by theory, adissociable hydrogen solvent may result in the hydrogenation of thedouble bond between carbons in an olefin such as ethylene. Further, thesolvent may be characterized as polar, as having a slight polarity, oras having unidirectional, electric charge. Not intending to be bound bytheory, a polar solvent may interact with and at least partiallysolubilize the salt.

In additional aspects, the liquid absorption solvent system canadditionally include a complexing agent in addition to the solvent. Inthis configuration, the liquid absorption solvent can be capable ofreversibly complexing with the olefin monomer. The complexing agent mayinclude a metallic salt. The metallic salt can include a salt of one ormore transition metals and a weakly-ionic halogen. Non-limiting examplesof suitable transition metals include silver, gold, copper, platinum,palladium, and nickel. Non-limiting examples of suitable weakly-ionichalogens include chlorine and bromine. In aspects, a suitable transitionmetal salt may be characterized as having a high specificity forolefins. Non-limiting examples of suitable transition metal-halogensalts include silver chloride (AgCl) and copper chloride (CuCl). In aparticular aspect, the salt employed in the liquid absorption solventsystem comprises CuCl. Not seeking to be bound by theory, such ametallic salt may interact with the double carbon bonds of olefinmonomers (e.g., ethylene).

In an aspect, the complexing agent may comprise a copper (I)carboxylate. Suitable copper (I) carboxylates include salts of copper(I) and mono-, di-, and/or tri-carboxylic acids containing 1-20 carbonatoms. The carboxylic acid component of the salt may comprise analiphatic constituent, a cyclic constituent, an aryl constituent, orcombinations thereof. Other suitable examples of copper (I) carboxylatesinclude Cu(I) formate, Cu(I) acetate, Cu(I) propionate, Cu(I) butyrate,Cu(I) pentanoate, Cu(I) hexanoate, Cu(I) octanoate, Cu(I) decanoate,Cu(I) 2-ethyl-hexoate, Cu(I) hexadecanoate, Cu(I) tetradecanoate, Cu(I)methyl formate, Cu(I) ethyl acetate, Cu(I) n-propyl acetate, Cu(I)n-butyl acetate, Cu(I) ethyl propanoate, Cu(I) octoate, Cu(I) benzoate,Cu(I) p-t-butyl benzoate, and the like. Additionally, the complexingagent can include an adduct of a copper (I) carboxylate, for example, asdisclosed herein, and boron trifluoride (BF₃).

In an additional and/or alternative aspect, the complexing agent maycomprise a copper (I) sulfonate. Non-limiting examples of suitablecopper (I) sulfonates include the copper (I) salts of sulfonic acidshaving 4 to 22 carbon atoms. The sulfonic acid component of the salt caninclude an aliphatic constituent, a cyclic constituent, an arylconstituent, or combinations thereof. The aliphatic sulfonic acids canbe straight chain or branched. Examples of suitable aliphatic sulfonicacids include, but are not limited to, n-butanesulfonic acid,2-ethyl-1-hexanesulfonic acid, 2-methylnonanesulfonic acid,dodecanesulfonic acid, 2-ethyl-5-n-pentyltridecanesulfonic acid,n-eicosanesulfonic acid, and the like. Examples of suitable aromaticsulfonic acids include benzenesulfonic acid, alkylbenzenesulfonic acidswherein the alkyl member contains from 1 to 16 carbon atoms, such asp-toluenesulfonic acid, dodecylbenzenesulfonic acid (o-, m-, and p-),p-hexadecylbenzenesulfonic acid, and the like, naphthalenesulfonic acid,phenolsulfonic acid, naphtholsulfonic acids, and halobenzenesulfonicacids, such as p-chlorobenzenesulfonic acid, p-bromobenzenesulfonicacid, and the like.

In an aspect, the complexing agent can also include a hindered olefin.For example, the complexing agent may additionally include a hinderedolefin when the complexing agent without the hindered olefin forms acopper complex with insufficient solubility in the solvent. An exampleof such a hindered olefin is a propylene tetramer (i.e. dodecene). Notintending to be bound by theory, the hindered olefin may increase thesolubility of the copper complex while being easily displaced byethylene.

In various embodiments, the absorption solvent system can utilize one ormore of the complexing agents disclosed in U.S. Pat. Nos. 5,104,570;5,191,153; 5,259,986; and 5,523,512, each of which is incorporated byreference in its entirety.

Particular embodiments of the liquid absorption solvent system includecopper chloride, aniline, and dimethylformamide (CuCl/aniline/DMF);alternatively, copper chloride, aniline, and N-methylpyrrolidone(CuCl/aniline/NMP); alternatively, copper (I) carboxylate and anaromatic solvent such as toluene or xylene; alternatively, copper (I)sulfonate and an aromatic solvent such as toluene or xylene;alternatively, an adduct of copper (I) carboxylate and BF₃ in anaromatic solvent such as toluene or xylene; alternatively, copper (I)2-ethyl-hexanoate and propylene tetramer; alternatively, copper (I)2-ethyl-hexanoate and dodecene; alternatively, copper (I) hexadecanoateand hexadecene; alternatively, copper (I) tetradecanoate andtetradecene.

Another example of the polishing apparatus 470 is found in U.S. Pat. No.5,769,927. In aspects, the polishing apparatus 470 can include acondenser, a flash tank, and a membrane filtration unit. The componentsof conduit 462 can be subject to condensation in the condenser so that aportion of the components condenses to a liquid phase while anotherportion of the components remains in the gas phase. The resulting liquidfrom condensation can then be subjected to flash separation in the flashtank to form a vapor from the condensed liquid and residual liquidportion. The resulting gas from condensation can be subjected tomembrane separation to recover the waste gases from the resulting gases.The residual liquid portion recovered from the flash step can includethe olefin monomer in conduit 402, which can be recycled to the firstreactor 100 and/or the MZCR 300, or otherwise consumed, treated,processed, and/or stored. The waste gases recovered from the membraneseparation step can include hydrogen, oxygen, nitrogen, carbon dioxide,or combinations thereof in conduit 406. These waste gases can be flared.

When utilizing a polishing apparatus 470 that has a condenser, flashtank, and membrane filtration unit, the components in conduit 462 can becompressed prior to feeding to the condenser. The temperature andpressure of the components in conduit 462 exiting the lightsdistillation column 460 can be a temperature which can range from about5° C. (41° F.) to about 20° C. (68° F.) and a pressure which can rangeof from about 0.101 MPa (14.7 psi) to about 0.586 MPa (85 psi). Thepressure after compression can be in a range of from about 0.689 MPag(100 psig) to about 6.89 MPag (1,000 psig); alternatively, from about0.689 MPag (100 psig) to about 3.45 MPag (500 psig); alternatively, fromabout 0.689 MPag (100 psig) to about 1.72 MPag (250 psig);alternatively, from about 1.38 MPag (200 psig) to about 6.89 MPag (1,000psig); alternatively, from about 1.38 MPag (200 psig) to about 3.45 MPag(500 psig); alternatively, from about 1.38 MPag (200 psig) to about 1.72MPag (250 psig). The temperature of the components in conduit 462 aftercompression may be slightly higher due to heat of compression.

In aspects, the condenser of the polishing apparatus 470 can be operatedat a temperature in a range of from about −100° C. (−148° F.) to about20° C. (68° F.); alternatively, from about −60° C. (−76° F.) to about20° C. (68° F.); alternatively, from about −40° C. (−40° F.) to about20° C. (68° F.). In additional aspects, the condenser of the polishingapparatus 470 can be operated at a pressure in a range of from about0.689 MPag (100 psig) to about 6.89 MPag (1,000 psig); alternatively,from about 0.689 MPag (100 psig) to about 3.45 MPag (500 psig);alternatively, from about 0.689 MPag (100 psig) to about 1.72 MPag (250psig); alternatively, from about 1.38 MPag (200 psig) to about 6.89 MPag(1,000 psig); alternatively, from about 1.38 MPag (200 psig) to about3.45 MPag (500 psig); alternatively, from about 1.38 MPag (200 psig) toabout 1.72 MPag (250 psig).

The temperature and pressure for operation of the flash tank of thepolishing apparatus 470 can be that which is suitable to bring theolefin monomer in the residual condensed liquid in a range of about 0MPa (0 psig) to about 0.345 MPag (50 psig) above the saturation vaporpressure of the olefin monomer at the temperature at which the flashtank is operated.

In aspects, the membrane filtration unit of the polishing apparatus 470can contain a membrane that exhibits a substantially differentpermeability for the olefin monomer gas than for the other gases (e.g.,nitrogen, hydrogen, carbon dioxide, oxygen, or combinations thereof)that are in the residual gas phase. The pressure of the residual gascomponents exiting the condenser can be sufficient to drive the pressuredrop across the membrane of the membrane filtration unit. The waste gasstream 406 exiting the membrane filtration unit can be greater than 5°C. (41° F.), alternatively, greater than 10° C. (50° F.) colder than thetemperature of the residual gas components that feed from the condenserto the membrane filtration unit.

The membrane can be relatively permeable to the olefin monomer andrelatively impermeable to the other gases, or relatively permeable tothe other gases and relatively impermeable to the monomer. Whenrelatively permeable to the olefin monomer, the conduit 406 used torecover the waste gases is connected to the retentate side of themembrane filtration unit; whereas, when relatively permeable to theother gases, the conduit 406 used to recover the waste gases isconnected to the permeate side of the membrane filtration unit.

Examples of membranes that are relatively permeable to the olefinmonomer include polymers that can be used to make elastomeric membranes,for example, nitrile rubber, neoprene, polydimethylsiloxane (siliconerubber), chlorosulfonated polyethylene, polysilicone-carbonatecopolymers, fluoroelastomers, plasticized polyvinylchloride,polyurethane, cis-polybutadiene, cis-polyisoprene, poly(butene-1),polystyrene-butadiene copolymers, styrene/butadiene/styrene blockcopolymers, styrene/ethylene/butylene block copolymers, thermoplasticpolyolefin elastomers, block copolymers of polyethers, polyamides,polyesters, or combinations thereof. Examples of membranes that arerelatively permeable to the other gases include polymers that can beused to make glassy membranes, for example, polysulfones, polyimides,polyamides, polyaramides, polyphenylene oxide, polycarbonates,ethylcellulose, cellulose acetate, or combinations thereof.

FIGS. 10A to 10F illustrate the first reactor 100 having variousadditional aspects not shown in FIG. 1 and FIG. 2.

FIGS. 10A to 10F show the first reactor 100 is in a fluidized bedreactor configuration (also referred to as a gas phase reactorconfiguration). In such a configuration, and as described for the firstreactor 100 in the description for FIGS. 1-2, the fluidized bed reactorcan include a gas recycle system, which in FIGS. 10A to 10F is formed byequipment 120, 130, 122, 140, 124, 150, and 126. Equipment 120, 122,124, and 126 are conduits; equipment 130 is a separator; equipment 140is a condenser; and equipment 150 is a compressor. Feed components feedinto the gas recycle system at conduit 124 via a combined feed conduit107. The combined feed conduit 107 contains a mixture of the olefinmonomer from conduit 102, the optional olefin comonomer from conduit104, the diluent from conduit 106. The catalyst (optionally as art of acatalyst system) can be fed directly to the reaction vessel of thefluidized bed reactor 100 via conduit 108. While FIGS. 10A to 10F showconduits 102, 104, and 106 feeding to the gas recycle system viaconduits 107 and 124, it is contemplated that the components in conduits102, 104, 106 can be fed to the first reactor 100 at any suitablelocation, including i) directly to the reaction vessel of the firstreactor 100, or ii) any of conduits 120, 122, 124, 126, and 133.Similarly, while FIGS. 10A to 10F show conduit 108 feeding to directlyto the reaction vessel, it is contemplated that the catalyst can be fedin conduit 108 to the first reactor 100 at any suitable location, suchas via any of conduits 107, 120, 122, 124, 126, and 133.

In operation, gaseous components flow from the top 101 of the firstreactor 100 into conduit 120 of the gas recycle system. While the firstreactor 100 can include a disengagement zone 114 configured to disengagethe gaseous components in the fluidized bed from the solid polyolefinparticles for flow in conduit 120, it is possible that some polyolefinparticles can flow along with the gaseous components out of the top 101of the first reactor 100 and into conduit 120.

In the gas recycle system of FIGS. 10A to 10F, an optional separator 130can be included to separate the polyolefin particles from the gaseouscomponents before the gaseous components enter downstream equipment suchas the condenser 140 and compressor 150 (e.g., to avoid fouling of thisequipment). The separator 130 can be configured as a settling tank or acyclone separator as described herein. The solid polyolefin particlesfall with the aid of gravity in the separator 130 and can separate fromthe gaseous components such that the solid olefin particles flow fromthe separator 130 in conduit 131, while the gaseous components continuealong the gas recycle system in conduit 122. The gaseous components inconduit 122 can then flow into a condenser 140 in the gas recycle systemthat is configured to condense at least one of the gaseous components,for example, the diluent or condensing agent, used in the gas phasepolymerization reactor. Condensation of the gaseous components forms agas/liquid mixture that flows from the condenser 140 via conduit 124.The gas/liquid mixture can be combined with any components fed to thefirst reactor 100 via conduit 107. The conditions of conduit 124 can besuch that diluent added via conduit 106 is in the liquid phase, whilethe olefin monomer added via conduit 102 is in the gas phase. It iscontemplated that the optional olefin comonomer, if present, can be inthe liquid phase or gas phase in conduit 124, depending on the boilingpoint of the olefin comonomer relative to the diluent/condensing agent.The gas/liquid mixture can then flow to in conduit 124 to compressor150. The compressor 150 is configured to increase the pressure of thegas/liquid mixture so as to provide additional conditions under whichthe diluent/condensing agent condenses in the gas recycle system. Thecompressed gas/liquid mixture flows from the compressor 150 via conduit126, back into the first reactor 100.

The solid polyolefin particles in conduit 131 can flow to a motivedevice 132. In an embodiment, the motive device 132 can be an eductor ofa configuration as described in FIG. 5A or FIG. 5B. A motive device 132embodied as an eductor can be appropriately sized for the smaller solidsflow rate than the comparative solids flow of eductor 375 described inFIGS. 5D to 5H. In an eductor embodiment, the motive device 132 canreceive the solid polyolefin particles in end 132 a, a carrier gas inend 132 b. The solid/gas mixture can exit end 132 c and can flow backinto the first reactor 100 via conduit 133. In an aspect, the carriergas can be sourced from the gaseous components in conduit 122, conduit201 (see FIGS. 1 and 2), conduit 501 (see FIGS. 1 and 2), conduit 502(see FIGS. 1 and 2), or combinations thereof. In another embodiment, themotive device 132 can be a solids pump configured to receive the solidpolyolefin particles from conduit 131 and to pump the solid polyolefinparticles to the first reactor 100 via conduit 133.

The first reactor 100 in FIGS. 10A, 10B, and 10C can be used in FIG. 1,where the first reactor product mixture exits the reactor 100 in productdischarge conduit 110. In each of FIGS. 10A, 10B, and 10C, a portion ofthe first reactor product mixture can flow from the product dischargeconduit 110 into a sampling system 1000 while the remaining portion ofthe first reactor product mixture can flow from the product dischargeconduit 110 into the product separation system 200.

The first reactor 100 as shown in FIGS. 10D, 10E, and 10F can be used inFIG. 2, where the first reactor product mixture containing themultimodal polyolefin exits the reactor 100 in product discharge conduit370. In each of FIGS. 10D, 10E, and 10F, a portion of the first reactorproduct mixture can flow from the product discharge conduit 370 into asampling system 1000 while the remaining portion of the first reactorproduct mixture can flow from the product discharge conduit 370 into theproduct separation system 400.

The sampling system 1000 in each of FIGS. 10A to 10F can be fluidlyconnected to the product discharge conduit 110 and configured to analyzea sample of the first polyolefin (for FIGS. 10A to 10C) or a sample ofthe multimodal polyolefin (for FIGS. 10D to 10F). The sampling system1000 can include a sample conduit 110 through which a portion of thefirst reactor product mixture flows to a sample flash tank 1010. Thesample flash tank 1010 can be configured to separate the solidpolyolefin (e.g., the first polyolefin for FIGS. 10A to 10C or themultimodal polyolefin for FIGS. 10D to 10E) from the gaseous componentssuch that the gaseous components can flow from the flash tank 1010 viaconduit 1011 and such that the solid polyolefin can flow from the flashtank 101 via conduit 1012. The solid polyolefin in conduit 1012 can flowto a sample analyzer 1020 that can be configured to analyze a sample ofthe first polyolefin to determine the one or more properties of thesolid polyolefin received via conduit 1012. The sample analyzer 1020 canbe configured to perform a Raman analysis, configured as a gaschromatograph, or configured as a spectroscopy device. Commerciallyavailable examples of the sample analyzer 1020 include the RAMANRXN3™Analyzer and the RAMANRXN4™ Analyzer.

FIGS. 10A to 10F also show a gas distributor 111 can be located inside abottom portion 115 of the fluidized bed reactor (i.e., the first reactor100). The gas distributor 111 can be configured with channels 111 athrough which the recycled gaseous components received from conduit 126can be distributed inside the reactor 100 as the gaseous components passthrough the gas distributor 111 into the polymerization zone 112 of thefirst reactor 100.

The unique aspects and product separation system 200 in each of FIGS.10A, 10B, and 10C will now be described.

FIG. 10A shows a settling leg 113 placed partially within the bottomportion 115 of the fluidized bed reactor. At least a portion of thesettling leg 113 can be placed inside the first reactor 100 such that anend 113 a of the settling leg 113 opens to the gas distributor 111and/or to the polymerization zone 112 and an opposite end 113 b extendsoutside the first reactor 100. While the settling leg 113 is shown inFIG. 10A as being positioned in a center of the gas distributor 111, itis contemplated that the settling leg 113 can be placed off-center withrespect to the gas distributor 111 and/or the reaction vessel of thefirst reactor 100.

The settling leg 113 can be in the form of a pipe. In an aspect, adiameter of the settling leg 113 is the same along the length of thesettling leg 113; while in another aspect, the end 113 b of the settlingleg 113 can be conically tapered such that the diameter of the end 113 bdecreases in the downward direction. In an aspect, the settling leg 113can have an inner diameter along the length of the settling leg in therange of from about 10.16 cm (4 inches) to about 30.48 cm (12 inches);alternatively, from about 15.24 cm (6 inches) to about 20.32 cm (8inches); alternatively, from about 23.32 cm (8 inches) to about 30.48 cm(12 inches), including any portion (e.g., end 113 b) that has an innerdiameter than changes along the length of said portion.

Solid polyolefin particles of the first polyolefin can fall by force ofgravity into the settling leg as the particles become too large for thefluidization forces to keep them fluidized in the polymerization zone112. The particles that settle out of the fluidized bed in the firstreactor 100 can flow into the end 113 a of the settling leg 113 to theopposite end 113 b of the settling leg 113 b. The particles can movedownward in the settling leg 113 from end 113 a to end 113 b as a movingbed in a plug-flow manner. The particles then can flow from the firstreactor 100 via product discharge conduit 110 to the product separationsystem 200.

The product separation system 200 in FIG. 10A can include a take-offvalve 210, a conduit 211, a separation vessel 230, conduit 201, andconduit 202. The product separation system 200 in FIG. 10B canoptionally further include the treater 1030.

The take-off valve 210 can be configured to receive the first reactorproduct mixture from the product discharge conduit 110 and to controlthe flow of the first reactor product mixture therethrough. The take-offvalve 210 can be any type of control valve known in the art to be usefulfor controlling flow of the product mixture. Such valves include ballvalves, v-ball valves, plug valves, globe valves and angle valves. In anaspect, the take-off valve 210 can have a diameter when 100% open in arange of from about 1.27 cm (0.5 inches) to about 7.62 cm (3 inches). Inan aspect, the take-off valve 210 can have a flow channel diametergreater than the largest expected polymer particle size even when thevalve 210 is required to be only a small amount open (for example,20-25% open), which gives a wide control range for the range of opennessof the take-off valve 210 (e.g., 20-100% open). The take-off valve 210may be actuated by a signal from a controller configured to operate thetake-off valve 210 in a continuous or a discontinuous manner. Thecontroller may be configured to fully close and then fully open thetake-off valve 210 at set intervals and for a certain duration, toactuate the take-off valve 210 to a percentage of openness, e.g.,20-100% open.

The separation vessel 230 can be coupled to the end 113 b of thesettling leg 113 via conduits 110 and 211 as well as via the take-offvalve 210. The separation vessel 230 can be configured to separate thefirst reactor product mixture into the first polyolefin in conduit 202and into a gas mixture in conduit 201. The gas mixture in conduit 201can include the gases separated from the first polyolefin. Theseparation vessel 230 can be embodied as a flash tank configured toprovide a reduction in pressure of the product mixture such that olefinmonomer, any optional olefin comonomer, diluent, and other components(e.g., nitrogen, hydrogen, oxygen, methane, ethane, propane, butane,isobutane, pentane, hexane, heavier hydrocarbons, or combinationsthereof) separate from the first polyolefin so as to yield one or moreof these gaseous components in conduit 201. To the extent that anyliquid is contained in the first reactor product mixture, the pressurereduction provided in the flash tank can flash the liquid into the gasphase for flow in conduit 201. In an aspect, the separation vessel 230can be a hollow vessel having a cone-shaped bottom portion that directsthe flow of the first polyolefin to conduit 202. In an aspect, theseparation vessel 230 can operate without a pressure reduction, forexample, when the first reactor product mixture contains gas componentsand the first polyolefin and no or a minimal amount of liquid, since areduction in pressure is not needed for flashing a liquid component to agas phase.

In an optional aspect, FIG. 10A illustrates a treater 1030 that can beconfigured to treat the gas mixture in conduit 201. That is, the treater1030 can be fluidly connected to the conduit 201. In aspects, thetreater 1030 can be a flare stack, a ground flare, a pressure swingabsorber, a membrane, or a combination thereof. In another optionalaspect, it is contemplated that the conduit 201 can flow to the productseparation system 400 for treatment of the gas mixture, as is describedfor FIG. 9.

FIG. 10B shows the product discharge conduit 110 placed on the side 116of the fluidized bed reactor. While placed on the side 116 of the vesselof the fluidized bed reactor, it is contemplated that the productdischarge conduit 110 can be placed on the bottom of the reactor vessel.The product discharge conduit 110 can be connected to the fluidized bedreactor such that an angle of the product discharge conduit 110 withrespect to horizontal is in a range of −60° to 60°; alternatively, −45°to 45°; alternatively, −35° to 35°; alternatively, −25° to 25°;alternatively, 0° to 45°; alternatively, in a range of 10° to 35°;alternatively, in a range of 20° to 25°. For example, the angle of theproduct discharge conduit 110 with respect to horizontal can be −60°,−59°, −58°, −57°, −56°, −55°, −57°, −56°, −55°, −54°, −53°, −52°, −51°,−50°, −49°, −48°, −47°, −46°, −45°, −44°, −43°, −42°, −41°, −40°, −39°,−38°, −37°, −36°, −35°, −34°, −33°, −32°, −31°, −30°, −29°, −28°, −27°,−26°, −25°, −24°, −23°, −22°, −21°, −20°, −19°, −18°, −17°, −16°, −15°,−14°, −13°, −12°, −11°, −10°, −9°, −8°, −7°, −6°, −5°, −4°, −3°, −2°,−1°, 0°, 1°, 2°, 3°, 4°, 5°, 6°, 7°, 80, 9°, 10°, 11°, 12°, 13°, 14°,15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°,29°, 30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°,43°, 44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°,57°, 58°, 59°, or 60°.

The product separation system 200 in FIG. 10B can include a lock hopper240, cycling valves 241 and 243, conduit 242, conduit 244, conduit 245,a separation vessel 230, conduit 201, and conduit 202. The productseparation system 200 in FIG. 10B can optionally further include thetreater 1030.

FIG. 10B shows that a lock hopper 240 can be coupled to the productdischarge conduit 110. In an aspect, the lock hopper 240 can be coupledto the product discharge conduit 110 by a first cycling valve 241 and aconduit 242. The lock hopper 240 can additionally be coupled to aseparation vessel 230 via a second cycling valve 243 and conduits 244and 245. The first cycling valve 241 can be coupled to an inlet 247 ofthe lock hopper 240, and the second cycling valve 243 can be coupled toan outlet 246 of the lock hopper 240. The first cycling valve 241 andthe second cycling valve 243 can be configured to pass the first reactorproduct mixture into and out of the lock hopper 240 while keeping thecontents inside the lock hopper 240 isolated from the conditions of thefluidized bed reactor and from the conditions of the separation vessel230. That is, at no time is the interior space of the lock hopper 240fluidly connected to the interior of the fluidized bed reactor or theinterior of the separation vessel 230. For example, the cycling valves241 and 243 can each have a plurality of chambers 248 and 249 that canbe cycled, for example if there are four chambers, by a quarter rotation(if two chambers, then a half rotation and so on for more chambers).Upon each partial rotation, one of the chambers 248 of the first cyclingvalve 241 can fluidly connect to the product discharge conduit 110 so asto receive first reactor product mixture therein, while another one ofthe chambers 248 can fluidly connect with the lock hopper 240 viaconduit 242 so that the first reactor product mixture falls down intothe lock hopper 240 via conduit 242. In a similar matter, upon eachpartial rotation, one of the chambers 249 of the second cycling valve243 can fluidly connect to the lock hopper 240 via conduit 244 so as toreceive first reactor product mixture therein, while another one of thechambers 249 can fluidly connect with the separation vessel 230 viaconduit 245 so that the first reactor product mixture falls down intothe separation vessel 230. A controller can be configured to control thepartial rotation of each of the first cycling valve 241 and the secondcycling valve 243 so as to maintain or change a desired amount of thefirst reactor product mixture inside the lock hopper 240.

The lock hopper 240 can be a vessel configured to receive the firstreactor product mixture and then pass the mixture out of the lock hopper240 according to actuation of the first cycling valve 241 and the secondcycling valve 243.

The separation vessel 230 can be coupled to the lock hopper 240 via thesecond cycling valve 243 and conduits 244 and 245. The separation vessel230 can be configured to separate the first reactor product mixture intothe first polyolefin in conduit 202 and into a gas mixture in conduit201. The gas mixture in conduit 201 can include the gases separated fromthe first polyolefin. The separation vessel 230 can be embodied as aflash tank configured to provide a reduction in pressure of the productmixture such that olefin monomer, any optional olefin comonomer,diluent, and other components (e.g., nitrogen, hydrogen, oxygen,methane, ethane, propane, butane, isobutane, pentane, hexane, heavierhydrocarbons, or combinations thereof) separate from the firstpolyolefin so as to yield one or more of these gaseous components inconduit 201. To the extent that any liquid is contained in the firstreactor product mixture, the pressure reduction provided in the flashtank can flash the liquid into the gas phase for flow in conduit 201. Inan aspect, the separation vessel 230 can be a hollow vessel having acone-shaped bottom portion that directs the flow of the first polyolefinto conduit 202. In an aspect, the separation vessel 230 can operatewithout a pressure reduction, for example, when the first reactorproduct mixture contains gas components and the first polyolefin and noor a minimal amount of liquid, since a reduction in pressure is notneeded for flashing a liquid component to a gas phase.

In an optional aspect, FIG. 10B illustrates a treater 1030 that can beconfigured to treat the gas mixture in conduit 201. That is, the treater1030 can be fluidly connected to the conduit 201. In aspects, thetreater 1030 can be a flare stack, a ground flare, a pressure swingabsorber, a membrane, or a combination thereof. In another optionalaspect, it is contemplated that the conduit 201 can flow to the productseparation system 400 for treatment of the gas mixture, as is describedfor FIG. 9.

FIG. 10C shows the product discharge conduit 110 placed on the side 116of the fluidized bed reactor. While placed on the side 116 of the vesselof the fluidized bed reactor, it is contemplated that the productdischarge conduit 110 can be placed on the bottom of the reactor vessel.The product discharge conduit 110 can be connected to the fluidized bedreactor such that an angle of the product discharge conduit 110 withrespect to horizontal is in a range of −60° to 60°; alternatively, −45°to 45°; alternatively, −35° to 35°; alternatively, −25° to 25°;alternatively, 0° to 45°; alternatively, in a range of 10° to 35°;alternatively, in a range of 20° to 25°. For example, the angle of theproduct discharge conduit 110 with respect to horizontal can be −60°,−59°, −58°, −57°, −56°, −55°, −57°, −56°, −55°, −54°, −53°, −52°, −51°,−50°, −49°, −48°, −47°, −46°, −45°, −44°, −43°, −42°, −41°, −40°, −39°,−38°, −37°, −36°, −35°, −34°, −33°, −32°, −31°, −30°, −29°, −28°, −27°,−26°, −25°, −24°, −23°, −22°, −21°, −20°, −19°, −18°, −17°, −16°, −15°,−14°, −13°, −12°, −11, −10°, −9°, −8°, −7°, −6°, −5°, −4, −3°, −2, −1,0, 1, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°, 16°,17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°, 30°,31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°, 44°,45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°, 58°,59°, or 60°.

The product separation system 200 in FIG. 10C can include a continuoustake-off valve 212, conduit 211, a separation vessel 230, conduit 201,and conduit 202. The product separation system 200 in FIG. 10C canoptionally further include the treater 1030.

FIG. 10C shows a continuous take-off valve 212 fluidly connected to theproduct discharge conduit 110. The continuous take-off valve 212 can beconfigured to receive the first reactor product mixture from the productdischarge conduit 110 and to control the flow of the first reactorproduct mixture therethrough. The continuous take-off valve 212 can beany type of control valve known in the art to be useful for controllingflow of the product mixture on a continuous basis. Such valves includeball valves, v-ball valves, plug valves, globe valves and angle valves.In an aspect, the continuous take-off valve 212 can have a flow channeldiameter greater than the largest expected polymer particle size evenwhen the valve 212 is required to be only a small amount open (forexample, 20-25% open), which gives a wide control range for the range ofopenness of the continuous take-off valve 212 (e.g., 20-100% open). Thecontinuous take-off valve 212 may be actuated by a signal from acontroller configured to operate the continuous take-off valve 212 suchthat the first reactor product mixture flows in the product dischargeconduit 110 in a continuous manner. The controller may be configured toactuate the continuous take-off valve 212 to a percentage of openness,e.g., 20-100% open.

The separation vessel 230 can be coupled to the continuous take-offvalve 212 via conduit 211. The separation vessel 230 can be configuredto separate the first reactor product mixture into the first polyolefinin conduit 202 and into a gas mixture in conduit 201. The gas mixture inconduit 201 can include the gases separated from the first polyolefin.The separation vessel 230 can be embodied as a flash tank configured toprovide a reduction in pressure of the product mixture such that olefinmonomer, any optional olefin comonomer, diluent, and other components(e.g., nitrogen, hydrogen, oxygen, methane, ethane, propane, butane,isobutane, pentane, hexane, heavier hydrocarbons, or combinationsthereof) separate from the first polyolefin so as to yield one or moreof these gaseous components in conduit 201. To the extent that anyliquid is contained in the first reactor product mixture, the pressurereduction provided in the flash tank can flash the liquid into the gasphase for flow in conduit 201. In an aspect, the separation vessel 230can be a hollow vessel having a cone-shaped bottom portion that directsthe flow of the first polyolefin to conduit 202. In an aspect, theseparation vessel 230 can operate without a pressure reduction, forexample, when the first reactor product mixture contains gas componentsand the first polyolefin and no or a minimal amount of liquid, since areduction in pressure is not needed for flashing a liquid component to agas phase.

In an optional aspect, FIG. 10C illustrates a treater 1030 that can beconfigured to treat the gas mixture in conduit 201. That is, the treater1030 can be fluidly connected to the conduit 201. In aspects, thetreater 1030 can be a flare stack, a ground flare, a pressure swingabsorber, a membrane, or a combination thereof. In another optionalaspect, it is contemplated that the conduit 201 can flow to the productseparation system 400 for treatment of the gas mixture, as is describedfor FIG. 9.

FIG. 10D shows a settling leg 113 placed partially within the bottomportion 115 of the fluidized bed reactor. At least a portion of thesettling leg 113 can be placed inside the first reactor 100 such that anend 113 a of the settling leg 113 opens to the gas distributor 111and/or to the polymerization zone 112 and an opposite end 113 b extendsoutside the first reactor 100. While the settling leg 113 is shown inFIG. 10D as being positioned in a center of the gas distributor 111, itis contemplated that the settling leg 113 can be placed off-center withrespect to the gas distributor 111 and/or the reaction vessel of thefirst reactor 100.

The settling leg 113 can be in the form of a pipe. In an aspect, adiameter of the settling leg 113 is the same along the length of thesettling leg 113; while in another aspect, the end 113 b of the settlingleg 113 can be conically tapered such that the diameter of the end 113 bdecreases in the downward direction. In an aspect, the settling leg 113can have an inner diameter along the length of the settling leg in therange of from about 10.16 cm (4 inches) to about 30.48 cm (12 inches),including any portion (e.g., end 113 b) that has an inner diameter thanchanges along the length of said portion.

Solid polyolefin particles of the first polyolefin can fall by force ofgravity into the settling leg as the particles become too large for thefluidization forces to keep them fluidized in the polymerization zone112. The particles that settle out of the fluidized bed in the firstreactor 100 can flow into the end 113 a of the settling leg 113 to theopposite end 113 b of the settling leg 113 b. The particles can movedownward in the settling leg 113 from end 113 a to end 113 b as a movingbed in a plug-flow manner. The particles then can flow from the firstreactor 100 via product discharge conduit 370 to the product separationsystem 200.

The product separation system 400 in FIG. 10D can include a take-offvalve 410, a conduit 411, a separation vessel 430, conduit 431, andconduit 401. The product separation system 400 in FIG. 10D canoptionally further include the treater 1030 and/or any combination ofequipment shown in and described for FIG. 9.

The take-off valve 410 can be configured to receive the first reactorproduct mixture from the product discharge conduit 370 and to controlthe flow of the first reactor product mixture therethrough. The take-offvalve 410 in FIG. 10D can be of a configuration for the take-off valvedescribed for FIG. 9.

The separation vessel 430 can be coupled to the end 113 b of thesettling leg 113 via conduits 110 and 411 as well as via the take-offvalve 410. The separation vessel 430 can be configured to separate thefirst reactor product mixture into the multimodal polyolefin in conduit401 and into a gas mixture in conduit 431. The gas mixture in conduit431 can include the gases separated from the first polyolefin. Theseparation vessel 430 can be a configuration for the separation vessel430 described for FIG. 9, for example, embodied as a flash tankconfigured to provide a reduction in pressure of the product mixturesuch that olefin monomer, any optional olefin comonomer, diluent, andother components (e.g., nitrogen, hydrogen, oxygen, methane, ethane,propane, butane, isobutane, pentane, hexane, heavier hydrocarbons, orcombinations thereof) separate from the multimodal polyolefin so as toyield one or more of these gaseous components in conduit 431. To theextent that any liquid is contained in the first reactor productmixture, the pressure reduction provided in the flash tank can flash theliquid into the gas phase for flow in conduit 431. In an aspect, theseparation vessel 430 can be a hollow vessel having a cone-shaped bottomportion that directs the flow of the multimodal polyolefin to conduit401. In an aspect, the separation vessel 430 can operate without apressure reduction, for example, when the first reactor product mixturecontains gas components and the multimodal polyolefin and no or aminimal amount of liquid, since a reduction in pressure is not neededfor flashing a liquid component to a gas phase.

In an optional aspect, FIG. 10D illustrates a treater 1030 that can beconfigured to treat the gas mixture in conduit 431. That is, the treater1030 can be fluidly connected to the conduit 431. In aspects, thetreater 1030 can be a flare stack, a ground flare, a pressure swingabsorber, a membrane, or a combination thereof. In alternative aspects,the treater 1030 can be the train of equipment shown in FIG. 9 thatprocesses the gaseous components received from conduit 431.

FIG. 10E shows the product discharge conduit 370 placed on the side 116of the fluidized bed reactor. While placed on the side 116 of the vesselof the fluidized bed reactor, it is contemplated that the productdischarge conduit 370 can be placed on the bottom of the reactor vessel.The product discharge conduit 370 can be connected to the fluidized bedreactor such that an angle of the product discharge conduit 370 withrespect to horizontal is in a range of −60° to 60°; alternatively, −45°to 45°; alternatively, −35° to 35°; alternatively, −25° to 25°;alternatively, 0° to 45°; alternatively, in a range of 10° to 35°;alternatively, in a range of 20° to 25°. For example, the angle of theproduct discharge conduit 370 with respect to horizontal can be −60°,−59°, −58°, −57°, −56°, −55°, −57°, −56°, −55°, −54°, −53°, −52°, −51°,−50°, −49°, −48°, −47°, −46°, −45°, −44°, −43°, −42°, −41°, −40°, −39°,−38°, −37°, −36°, −35°, −34°, −33°, −32°, −31°, −30°, −29°, −28°, −27°,−26°, −25°, −24°, −23°, −22°, −21°, −20°, −19°, −18°, −17°, −16°, −15°,−14°, −13°, −12°, −11°, −10°, −9°, −8°, −7°, −6°, −5°, −4°, −3°, −2°,−1, 0, 1, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12, 13°, 14°, 15°,16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°,30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°,44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°,58°, 59°, or 60°.

The product separation system 400 in FIG. 10E can include a lock hopper490, cycling valves 491 and 493, conduit 492, conduit 494, conduit 495,a separation vessel 430, conduit 401, and conduit 431. The productseparation system 400 in FIG. 10E can optionally further include thetreater 1030 and/or any combination of equipment shown in and describedfor FIG. 9.

FIG. 10E shows that a lock hopper 490 can be coupled to the productdischarge conduit 370. In an aspect, the lock hopper 490 can be coupledto the product discharge conduit 370 by a first cycling valve 491 and aconduit 492. The lock hopper 490 can additionally be coupled to aseparation vessel 430 via a second cycling valve 493 and conduits 495and 495. The first cycling valve 491 can be coupled to an inlet 497 ofthe lock hopper 490, and the second cycling valve 493 can be coupled toan outlet 496 of the lock hopper 490. The first cycling valve 491 andthe second cycling valve 493 can be configured to pass the first reactorproduct mixture into and out of the lock hopper 490 while keeping thecontents inside the lock hopper 490 isolated from the conditions of thefluidized bed reactor and from the conditions of the separation vessel430. That is, at no time is the interior space of the lock hopper 490fluidly connected to the interior of the fluidized bed reactor or theinterior of the separation vessel 430. For example, the cycling valves491 and 493 can each have a plurality of chambers 498 and 499 that canbe cycled, for example if there are four chambers, by a quarter rotation(if two chambers, then a half rotation and so on for more chambers).Upon each partial rotation, one of the chambers 498 of the first cyclingvalve 491 can fluidly connect to the product discharge conduit 370 so asto receive first reactor product mixture therein, while another one ofthe chambers 498 can fluidly connect with the lock hopper 490 viaconduit 492 so that the first reactor product mixture falls down intothe lock hopper 490 via conduit 492. In a similar matter, upon eachpartial rotation, one of the chambers 499 of the second cycling valve493 can fluidly connect to the lock hopper 490 via conduit 494 so as toreceive first reactor product mixture therein, while another one of thechambers 499 can fluidly connect with the separation vessel 430 viaconduit 495 so that the first reactor product mixture falls down intothe separation vessel 430. A controller can be configured to control thepartial rotation of each of the first cycling valve 491 and the secondcycling valve 493 so as to maintain or change a desired amount of thefirst reactor product mixture inside the lock hopper 490.

The lock hopper 490 can be a vessel configured to receive the firstreactor product mixture and then pass the mixture out of the lock hopper490 according to actuation of the first cycling valve 491 and the secondcycling valve 493.

The separation vessel 430 can be coupled to the lock hopper 490 via thesecond cycling valve 493 and conduits 494 and 495. The separation vessel430 can be a configuration for the separation vessel 430 described forFIG. 9, for example, embodied as a flash tank configured to provide areduction in pressure of the product mixture such that olefin monomer,any optional olefin comonomer, diluent, and other components (e.g.,nitrogen, hydrogen, oxygen, methane, ethane, propane, butane, isobutane,pentane, hexane, heavier hydrocarbons, or combinations thereof) separatefrom the multimodal polyolefin so as to yield one or more of thesegaseous components in conduit 431. To the extent that any liquid iscontained in the first reactor product mixture, the pressure reductionprovided in the flash tank can flash the liquid into the gas phase forflow in conduit 431. In an aspect, the separation vessel 430 can be ahollow vessel having a cone-shaped bottom portion that directs the flowof the multimodal polyolefin to conduit 401. In an aspect, theseparation vessel 430 can operate without a pressure reduction, forexample, when the first reactor product mixture contains gas componentsand the multimodal polyolefin and no or a minimal amount of liquid,since a reduction in pressure is not needed for flashing a liquidcomponent to a gas phase.

In an optional aspect, FIG. 10E illustrates a treater 1030 that can beconfigured to treat the gas mixture in conduit 431. That is, the treater1030 can be fluidly connected to the conduit 431. In aspects, thetreater 1030 can be a flare stack, a ground flare, a pressure swingabsorber, a membrane, or a combination thereof. In another optionalaspect, it is contemplated that the conduit 431 can flow to the productseparation system 400 for treatment of the gas mixture, as is describedfor FIG. 9.

FIG. 10F shows the product discharge conduit 370 placed on the side 116of the fluidized bed reactor. While placed on the side 116 of the vesselof the fluidized bed reactor, it is contemplated that the productdischarge conduit 370 can be placed on the bottom of the reactor vessel.The product discharge conduit 370 can be connected to the fluidized bedreactor such that an angle of the product discharge conduit 370 withrespect to horizontal is in a range of −60° to 60°; alternatively, −45°to 45°; alternatively, −35° to 35°; alternatively, −25° to 25°;alternatively, 0° to 45°; alternatively, in a range of 10° to 35°;alternatively, in a range of 20° to 25°. For example, the angle of theproduct discharge conduit 370 with respect to horizontal can be −60°,−59°, −58°, −57°, −56°, −55°, −57°, −56°, −55°, −54°, −53°, −52°, −51°,−50°, −49°, −48°, −47°, −46°, −45°, −44°, −43°, −42°, −41°, −40°, −39°,−38°, −37°, −36°, −35°, −34°, −33°, −32°, −31°, −30°, −29°, −28°, −27°,−26°, −25°, −24°, −23°, −22°, −21°, −20°, −19°, −18°, −17°, −16°, −15°,−14°, −13°, −12°, −11°, −10°, −9°, −8°, −7°, −6°, −5°, −4°, −3°, −2°,−1°, 0, 1, 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, 11°, 12°, 13°, 14°, 15°,16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, 26°, 27°, 28°, 29°,30°, 31°, 32°, 33°, 34°, 35°, 36°, 37°, 38°, 39°, 40°, 41°, 42°, 43°,44°, 45°, 46°, 47°, 48°, 49°, 50°, 51°, 52°, 53°, 54°, 55°, 56°, 57°,58°, 59°, or 60°.

The product separation system 400 in FIG. 10F can include a continuoustake-off valve 413, conduit 411, a separation vessel 430, conduit 401,and conduit 431. The product separation system 400 in FIG. 10E canoptionally further include the treater 1030 and/or any combination ofequipment shown in and described for FIG. 9.

FIG. 10F shows a continuous take-off valve 413 fluidly connected to theproduct discharge conduit 370. The continuous take-off valve 413 can beconfigured to receive the first reactor product mixture from the productdischarge conduit 370 and to control the flow of the first reactorproduct mixture therethrough. The continuous take-off valve 413 can beany type of control valve known in the art to be useful for controllingflow of the product mixture on a continuous basis. Such valves includeball valves, v-ball valves, plug valves, globe valves and angle valves.In an aspect, the continuous take-off valve 413 can have a flow channeldiameter greater than the largest expected polymer particle size evenwhen the valve 413 is required to be only a small amount open (forexample, 20-25% open), which gives a wide control range for the range ofopenness of the continuous take-off valve 413 (e.g., 20-100% open). Thecontinuous take-off valve 413 may be actuated by a signal from acontroller configured to operate the continuous take-off valve 413 suchthat the first reactor product mixture flows in the product dischargeconduit 370 in a continuous manner. The controller may be configured toactuate the continuous take-off valve 413 to a percentage of openness,e.g., 20-100% open.

The separation vessel 430 can be coupled to the continuous take-offvalve 413 via conduit 411. The separation vessel 430 can be configuredto separate the first reactor product mixture into the first polyolefinin conduit 401 and into a gas mixture in conduit 431. The gas mixture inconduit 431 can include the gases separated from the first polyolefin.The separation vessel 430 can be embodied as a flash tank configured toprovide a reduction in pressure of the product mixture such that olefinmonomer, any optional olefin comonomer, diluent, and other components(e.g., nitrogen, hydrogen, oxygen, methane, ethane, propane, butane,isobutane, pentane, hexane, heavier hydrocarbons, or combinationsthereof) separate from the first polyolefin so as to yield one or moreof these gaseous components in conduit 431. To the extent that anyliquid is contained in the first reactor product mixture, the pressurereduction provided in the flash tank can flash the liquid into the gasphase for flow in conduit 431. In an aspect, the separation vessel 430can be a hollow vessel having a cone-shaped bottom portion that directsthe flow of the first polyolefin to conduit 401. In an aspect, theseparation vessel 430 can operate without a pressure reduction, forexample, when the first reactor product mixture contains gas componentsand the first polyolefin and no or a minimal amount of liquid, since areduction in pressure is not needed for flashing a liquid component to agas phase.

In an optional aspect, FIG. 10F illustrates a treater 1030 that can beconfigured to treat the gas mixture in conduit 431. That is, the treater1030 can be fluidly connected to the conduit 431. In aspects, thetreater 1030 can be a flare stack, a ground flare, a pressure swingabsorber, a membrane, or a combination thereof. In another optionalaspect, it is contemplated that the conduit 431 can flow to the productseparation system 400 for treatment of the gas mixture, as is describedfor FIG. 9.

The disclosed apparatuses and processes are configured to producemultimodal polyolefins.

In aspect, the multimodal polyolefins can comprise high densitypolyethylene (HDPE), medium density polyethylene (MDPE), low densitypolyethylene (LDPE), linear low density polyethylene (LLDPE), orcombinations thereof. Any of the HDPE, MDPE, LDPE, LLDPE can be producedas a homopolymer or a copolymer (e.g., a polyolefin containing ethylenemonomer units and comonomer units of a comonomer disclosed herein suchas 1-hexene).

Other aspects and embodiments of the multimodal polyolefin compositionsproduced according to this disclosure are described as polyethyleneresins A, B, C, D, and E below. Each polyethylene resin A, B, C, D, andE can comprise the first polyolefin made in polymerization zone 112 ofthe first reactor 100, the second polyolefin made in the polymerizationzone 321 of the riser 320 of the MZCR 300, and the third polyolefin madein the polymerization zone 341 of the downcomer 340 of the MZCR 300.

In an aspect, the first polyolefin can be a HDPE resin and the secondand third polyolefins can together form a LLDPE.

In an aspect, the first polyolefin in each polyethylene resin A, B, C,D, and E can be a low molecular weight (LMW) component of the multimodalpolyolefin, the second polyolefin in each polyethylene resin A, B, C, D,and E can be an intermediate molecular weight (IMW) component of themultimodal polyolefin, and the third polyolefin in each polyethyleneresin A, B, C, D, and E can be a high molecular weight component (HMW)of the multimodal polyolefin. It is contemplated that an amount ornumber of other components of the multimodal polyolefin may be presentdue to residual polymerization reactions that can occur in MZCR 300, forexample, in one or more of the lower conduit 310, the upper conduit 330,and the separator 350 of the MZCR 300. Thus, in an aspect, themultimodal polyolefin (and thus in each polyethylene resin A, B, C, D,and E) can have from three to six molecular weight components and can becharacterized as a trimodal polyolefin, a quadramodal polyolefin, apentamodal polyolefin, or a hexamodal polyolefin.

In an aspect, the first polyolefin in each polyethylene resin A, B, C,D, and E can be a low molecular weight (LMW) component of the multimodalpolyolefin, the second polyolefin in each polyethylene resin A, B, C, D,and E can be an intermediate molecular weight (IMW) component of themultimodal polyolefin, and the third polyolefin in each polyethyleneresin A, B, C, D, and E can be a high molecular weight component (HMW)of the multimodal polyolefin. It is contemplated that an amount of othercomponents of the multimodal polyolefin may be present due to residualpolymerization reactions that can occur in MZCR 300, for example, in oneor more of the lower conduit 310, the upper conduit 330, and theseparator 350 of the MZCR 300.

In additional or alternative aspects, the first polyolefin (e.g., theLMW component) in each polyethylene resin A, B, C, D, and E that isproduced in the polymerization zone 112 of the first reactor 100 can bea lower molecular weight polyethylene, and the third polyolefin (e.g.,the HMW component) in each polyethylene resin A, B, C, D, and E that isproduced in the polymerization zone 341 of the downcomer 340 can be ahigher molecular weight polyethylene. The second polyolefin (e.g., theIMW component) in each polyethylene resin A, B, C, D, and E that isproduced in the polymerization zone 321 of the riser 320. The terms“lower” and “higher” are used to describe the average molecular weightof a polyolefin relative to the average molecular weight of otherpolyolefins in the multimodal polyolefin composition, and are not meantto include only absolute values as recognized by those skilled in theart (e.g., “lower molecular weight” does not necessarily mean theaverage molecular weight has a “low” molecular weight, although verywell could be). Thus, when the polyolefin produced in the polymerizationzone 112 has a “lower molecular weight”, it is intended that thepolyolefin has an average molecular weight that is lower than theaverage molecular weight of other polyolefins in the multimodalpolyolefin composition, e.g., lower than the “higher molecular weight”of the polyolefin made in the downcomer 340 and the intermediatemolecular weight of the polyolefin made in the riser 320. Likewise, whenthe polyolefin produced in the polymerization zone 341 of the downcomer340 has a “higher molecular weight” it is intended that the polyolefinhas an average molecular weight that is higher than the molecular weightof other polyolefins in the multimodal polyolefin composition, e.g.,higher than the “lower molecular weight” of the polyolefin made in thefirst reactor 100 and the intermediate molecular weight of thepolyolefin made in the riser 320.

The multiple polymerization zones (e.g., polymerization zones 112, 321,and 341) in the disclosed apparatuses and processes give greatflexibility in the properties of the multimodal polyolefins that can bemade. The residence times, gas compositions, catalyst, catalystinjection rate, ratio of olefin monomer to catalyst, comonomerconcentration, hydrogen concentration, and other parameters in thepolymerization zones 112, 321, and 341 can be determined to produce amultimodal polyolefin having desirable properties.

One advantage of the multimodal polyolefins disclosed herein is theiruse in lightweighting. Lightweighting occurs when less of a multimodalpolyolefin is used to form a pipe, film, or article than would otherwisebe used, for example with a bimodal polyolefin, to form the same size ofpipe, film, or article. The multimodal polyolefins that can be producedherein can have advantageous stiffness and Young's, Secant, and/orFlexural modulus values that enable lightweighting when forming a pipe,film, or article, while still having desired impact strength andenvironmental stress cracking resistance (ESCR) in the formed pipe,film, or article. Without being limited by theory, it is believed thatthe disclosed processes and apparatuses can be used to control theamount of the first polyolefin (also can be referred to as the lowmolecular weight (LMW) component) that is incorporated into themultimodal polyolefin. The control can be for an amount of the LMWcomponent that advantageously leads to lightweighting when themultimodal polyolefin is used to produce pipe, film, or an article.

Another advantage of the multimodal polyolefins disclosed herein is alower amount of gels in resins suitable for use as pipe. The lower gelcount results in improved mechanical properties, aesthetics, and surfacefinish of the product. Generally, gels are higher molecular weightand/or crosslinked polymers (e.g., polyethylene) in the form of discreteparticles. For purposes of counting these discrete particles, acountable gel has greater than 200 microns in size. Gels in themultimodal polyolefins (including the polyethylene resins disclosedherein) can be measured by extruding a 1 mm thick cast film on a 1.25″Killion single screw extruder with a slot die. An FS5 model OCS (OpticalControl Systems, GmbH) gel counter with a light source can be used intransmission mode with the grey level set at 170 to detect the number ofgels. Fewer gels are formed because the multiple zone polyolefinpolymerizations disclosed herein produce a more homogeneous product. Themultimodal molecular weight distribution can allow bridging of the lowmolecular weight (LMW) component and the high molecular weight (HMW)component with one or more other components such that the multimodalpolyolefin has fewer gels that result when mixing components havingdisparate molecular weights (e.g., a HMW component and a LMW component).

Polyethylene resins A, B, C, D, and E are discussed below as exemplaryembodiments of the multimodal polyolefins that can be made in thedisclosed apparatuses and processes, and it is contemplated that otherpolyolefin resins can be made. In aspect, any multimodal polyolefin andany polyolefin resin made herein can be suitable for use as a film, apipe, or an article formed by blow molding, small part blow molding,large part blow molding, extrusion molding, rotational molding,thermoforming, cast molding, and the like.

In an aspect, an amount of from about 20 to about 80 wt. %,alternatively from about 40 to about 60 wt. %, alternatively from about45 to about 55 wt. %, alternatively about 50 wt. % of polyethylene resinA can comprise the first polyolefin and an amount of from about 80 toabout 20 wt. %, alternatively from about 60 to about 40 wt. %,alternatively from about 55 to about 45 wt. %, alternatively about 50wt. % of polyethylene resin A can comprise the second polyolefin and thethird polyolefin. Stated another way, an amount of from about 20 toabout 80 wt. %, alternatively from about 40 to about 60 wt. %,alternatively from about 45 to about 55 wt. %, alternatively about 50wt. % of polyethylene resin A can comprise the LMW component and anamount of from about 80 to about 20 wt. %, alternatively from about 60to about 40 wt. %, alternatively from about 55 to about 45 wt. %,alternatively about 50 wt. % of polyethylene resin A can comprise theIMW component and the HMW component. Stated another way, the LMWcomponent of polyethylene resin A can be present in an amount of fromabout 20 wt. % to about 75 wt. %, the IMW component of polyethyleneresin A can be present in an amount of from about 5 wt. % to about 40wt. %, and the HMW component of polyethylene resin A can be present inan amount of from about 10 wt. % to about 60 wt. %.

In an aspect, the portion of polyethylene resin A that is made of thesecond polyolefin and the third polyolefin can include an amount of fromabout 1 to about 30 wt. % of the second polyolefin and an amount of fromabout 10 to about 79 wt. % of the third polyolefin.

In an aspect, the portion of polyethylene resin A that is made of theIMW component and the HMW component can include an amount of from about1 to about 30 wt. % of the IMW component and an amount of from about 10to about 79 wt. % of the HMW component.

In an aspect, polyethylene resin A can have a density in a range ofabout 0.930 to about 0.970 g/ml, when tested in accordance with ISO 1183at 23° C.

In an aspect, polyethylene resin A can have a melt index (MI₂) in arange of from about 0.1 to about 30 g/10 min, when tested in accordancewith ISO 1133 at 190° C. under a force of 2.16 kg.

In an aspect, polyethylene resin A can have a high load melt index(HLMI) of from about 1 to about 45 g/10 min, when tested in accordancewith ISO 1133 at 190° C. under a force of 2.16 kg.

In an aspect, polyethylene resin A can have a comonomer content in arange of from about 0 to about 6 wt. %.

In an aspect, polyethylene resin A can have a weight average molecularweight (M_(w)) in a range of from about 250 to about 1,500 kg/mol.

In an aspect, polyethylene resin A can have a number average molecularweight (M_(n)) in a range of from about 4.8 to about 84 kg/mol.

In an aspect, polyethylene resin A can have a z-average molecular weight(M_(z)) in a range of from about 500 to about 5,000 kg/mol.

In an aspect, polyethylene resin A can have a polydispersity index(dispersity or PDI or M_(w)/M_(n)) in a range of from about 18 to about52.

In an aspect, polyethylene resin A can have a long chain branching indexin a range of from about 0 to about 0.96.

In an aspect, polyethylene resin A can have a shear inducedcrystallization (SIC) index in a range of from about 0.15 to about 8.The SIC index is determined by the following equation: SICindex=(t_(onset,SIC)@1000×t_(onset,quiescent))/(HLMI*100) wheret_(onset,SIC)@1000 is measured in seconds and is the time required forcrystallization onset under shear rate of 1000 s⁻¹, and wheret_(onset, quiescent) is measured in seconds and is the crystallizationonset time at a temperature of 125° C. under no shear, determined inisothermal mode by differential scanning calorimetry.

In an aspect, the second polyolefin (e.g., the IMW component) ofpolyethylene resin A that is produced in polymerization zone 321 of theriser 320 can have an average molecular weight (M_(w), M_(n), or M_(z))greater than an average molecular weight (M_(w), M_(n), or M_(z)) of thefirst polyolefin (e.g., the LMW component) of polyethylene resin A thatis produced in the polymerization zone 112 of the first reactor 100 andless than an average molecular weight (M_(w), M_(n), or M_(z)) of thethird polyolefin (e.g., the HMW component) of polyethylene resin A thatis produced in the polymerization zone 341 of the downcomer 340.

In an aspect, polyethylene resin A can have an environmental stresscracking resistance (ESCR) of equal to or greater than about 800 hours;alternatively, greater than about 900 hours; alternatively, greater thanabout 1,000 hours, when tested in accordance with ISO 16770.

In an aspect, polyethylene resin A can have a value for rapid crackpropagation (RCP) that is at least 100%; alternatively, at least 110%;alternatively, at least 120%; alternatively, at least 130%;alternatively, at least 140% of the value for RCP of a bimodalpolyethylene.

In an aspect, polyethylene resin A can have a value for rapid crackpropagation (RCP) that is at least 100%; alternatively, at least 110%;alternatively, at least 120%; alternatively, at least 130%;alternatively, at least 140% of the value for RCP of a bimodalpolyethylene.

In an aspect, polyethylene resin A can have a resistance to slow crackgrowth of at least 100%; alternatively, at least 110%; alternatively, atleast 120%; alternatively, at least 130%; alternatively, at least 140%of the value for resistance to slow crack growth of a bimodalpolyethylene, when tested in accordance with ASTM F1473, with the caveatthat the resistance to slow crack growth is defined as the polyethylenenotch tensile test (PENT) failure time.

In an aspect, polyethylene resin A can have a tensile impact strength offrom about 135 to about 165 kJ/m².

In an aspect, polyethylene resin A can have a gel count of less thanabout 950 gels/m². Alternatively, polyethylene resin A can have a gelcount of less than about 900 gels/m²; alternatively, less than about 850gels/m²; alternatively, less than about 800 gels/m²; alternatively, lessthan about 750 gels/m²; alternatively, a gel count of less than about700 gels/m²; alternatively, less than about 650 gels/m²; alternatively,less than about 600 gels/m².

In an aspect, polyethylene resin A can be made by an embodiment of theprocess having a combination of the aspects described herein.

In an aspect, polyethylene resin A can be suitable for use as a film, apipe, or an article formed by blow molding, small part blow molding,large part blow molding, extrusion molding, rotational molding,thermoforming, cast molding, and the like.

In an aspect, an amount of from about 20 to about 75 wt. % ofpolyethylene resin B can comprise the first polyolefin, an amount offrom about 5 to about 40 wt. % of polyethylene resin B can comprise thesecond polyolefin, and an amount of from about 10 to about 60 wt. % ofpolyethylene resin B can comprise the third polyolefin. Stated anotherway, an amount of from about 20 to about 75 wt. % of polyethylene resinB can comprise the LMW component, an amount of from about 5 to about 40wt. % of polyethylene resin B can comprise the IMW component, and anamount of from about 10 to about 60 wt. % of polyethylene resin B cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin B can be present in an amount of from about 20 wt. %to about 75 wt. %, the IMW component of polyethylene resin B can bepresent in an amount of from about 5 wt. % to about 40 wt. %, and theHMW component of polyethylene resin B can be present in an amount offrom about 10 wt. % to about 60 wt. %.

In an aspect, polyethylene resin B can be a trimodal polyethylene resin.

In aspect, an amount of from about 40 to about 60 wt. % of polyethyleneresin B can comprise the first polyolefin, an amount of from about 20 toabout 40 wt. % of polyethylene resin B can comprise the secondpolyolefin, and an amount of from about 10 to about 30 wt. % ofpolyethylene resin B can comprise the third polyolefin. Stated anotherway, an amount of from about 40 to about 60 wt. % of polyethylene resinB can comprise the LMW component, an amount of from about 20 to about 40wt. % of polyethylene resin B can comprise the IMW component, and anamount of from about 10 to about 30 wt. % of polyethylene resin B cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin B can be present in an amount of from about 40 wt. %to about 60 wt. %, the IMW component of polyethylene resin B can bepresent in an amount of from about 20 wt. % to about 40 wt. %, and theHMW component of polyethylene resin B can be present in an amount offrom about 10 wt. % to about 30 wt. %.

In aspect, an amount of from about 50 wt. % of polyethylene resin B cancomprise the first polyolefin, an amount of from about 30 wt. % ofpolyethylene resin B can comprise the second polyolefin, and an amountof from about 20 wt. % of polyethylene resin B can comprise the thirdpolyolefin. Stated another way, an amount of from about 50 wt. % ofpolyethylene resin B can comprise the LMW component, an amount of fromabout 30 wt. % of polyethylene resin B can comprise the IMW component,and an amount of from about 20 wt. % of polyethylene resin B cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin B can be present in an amount of from about 50 wt. %,the IMW component of polyethylene resin B can be present in an amount offrom about 30 wt. %, and the HMW component of polyethylene resin B canbe present in an amount of from about 20 wt. %.

In an aspect, polyethylene resin B can have a long chain branchingcontent of less than about 0.01 long chain branches per 1,000 carbonatoms.

In an aspect, polyethylene resin B can be a copolymer formed using acomonomer in at least one of the first reactor 100 and the MZCR 300. Thecopolymer can have a comonomer content of from greater than about 0 wt.% to about 20 wt. %; alternatively, from greater than about 0 wt. % toabout 6 wt. %; alternatively, from about 2 wt. % to about 6 wt. %;alternatively, from about 1 wt. % to about 5 wt. %; alternatively, fromgreater than about 6 wt. % to about 20 wt. %; alternatively, fromgreater than about 6 wt. % to about 15 wt. %; or alternatively, fromgreater than about 6 wt. % to about 10 wt. %.

In an aspect, the comonomer for polyethylene resin B can be 1-butene,1-hexene, 1-octene, or combinations thereof.

In an aspect, polyethylene resin B can have density of from about 0.900g/cc to about 0.980 g/cc, when tested in accordance with ASTM D1505;alternatively, a density of less than about 0.960 g/cc, when tested inaccordance with ASTM D1505; alternatively, a density of from greaterthan about 0.940 g/cc to about 0.960 g/cc, when tested in accordancewith ASTM D1505; alternatively, a density of from about 0.920 g/cc toabout 0.940 g/cc, when tested in accordance with ASTM D1505.

In an aspect, polyethylene resin B can have a melt index (MI₂) of lessthan about 1 g/10 min, when tested in accordance with ASTM D1238 under aforce of 2.16 kg.

In an aspect, polyethylene resin B can have a high load melt index(HLMI) of from about 1 g/10 min to less than about 20 g/10 min, whentested in accordance with ASTM D1238 under a force of 21.6 kg.

In an aspect, polyethylene resin B can have a weight average molecularweight (M_(w)) of from about 150 kg/mol to about 1,000 kg/mol.

In an aspect, polyethylene resin B can have a number average molecularweight (M_(n)) of from about 7.5 kg/mol to about 30 kg/mol.

In an aspect, polyethylene resin B can have a z-average molecular weight(M_(z)) of from about 1,000 kg/mol to about 5,000 kg/mol; alternatively,from about 1,000 kg/mol to about 3,500 kg/mol.

In an aspect, polyethylene resin B can have a (z+1)-average molecularweight (M_(z+1)) of from about 2,000 kg/mol to about 9,000 kg/mol.

In an aspect, polyethylene resin B can have a polydispersity index(dispersity or PDI or M_(w)/M_(n)) of from about 5 to about 60.

In an aspect, polyethylene resin B can have a polydispersity index(dispersity or PDI or M_(w)/M_(n)) of less than about 18.

In an aspect, polyethylene resin B can have a magnitude of slip-stick offrom about 300 psi to about 1,000 psi (about 2.07 MPa to about 6.89MPa).

In an aspect, the LMW component of polyethylene resin B is ahomopolymer.

In an aspect, the LMW component of polyethylene resin B can have adensity of less than about 0.960 g/cc or alternatively, from equal to orgreater than about 0.960 g/cc to about 0.985 g/cc, when tested inaccordance with ASTM D1505.

In an aspect, the LMW component of polyethylene resin B can have a meltindex (MI₂) of from about 3 g/10 min to about 400 g/10 min, when testedin accordance with ASTM D1238 under a force of 2.16 kg.

In an aspect, the LMW component of polyethylene resin B can have a highload melt index (HLMI) of from about 160 g/10 min to about 41,000 g/10min, when tested in accordance with ASTM D1238 under a force of 21.6 kg.

In an aspect, the LMW component of polyethylene resin B can have aweight average molecular weight (M_(w)) of from about 20 kg/mol to about150 kg/mol.

In an aspect, the LMW component of polyethylene resin B can have anumber average molecular weight (M_(n)) of from about 5 kg/mol to about25 kg/mol; alternatively, from about 5 kg/mol to about 15 kg/mol.

In an aspect, the LMW component of polyethylene resin B can have az-average molecular weight (M_(z)) of from about 100 kg/mol to about 340kg/mol.

In an aspect, the LMW component of polyethylene resin B can have apolydispersity index (dispersity or PDI or M_(w)/M_(n)) of from about 1to about 30; alternatively, from about 1 to about 15.

In an aspect, the LMW component of polyethylene resin B can have a shortchain branching content of from about 0 to about 5 short chain branchesper 1,000 carbon atoms; alternatively, from about 0 to about 4 shortchain branches per 1,000 carbon atoms; alternatively, from about 0 toabout 3 short chain branches per 1,000 carbon atoms; alternatively, fromabout 0 to about 2 short chain branches per 1,000 carbon atoms;alternatively, from about 0 to about 1 short chain branches per 1,000carbon atoms.

In an aspect, the IMW component of polyethylene resin B can be acopolymer.

In an aspect, the IMW component of polyethylene resin B can have a firstcomonomer content of from greater than about 0 wt. % to about 10 wt. %;alternatively, from greater than about 0 wt. % to about 4 wt. %.

In an aspect, the IMW component if polyethylene resin B can have adensity of from equal to or greater than about 0.915 g/cc to about 0.970g/cc, when tested in accordance with ASTM D1505.

In an aspect, the IMW component of polyethylene resin B can have a meltindex (MI₂) of from about 0.1 g/10 min to about 30 g/10 min, when testedin accordance with ASTM D1238 under a force of 2.16 kg.

In an aspect, the IMW component of polyethylene resin B can have a highload melt index (HLMI) of from about 5 g/10 min to about 1,500 g/10 min,when tested in accordance with ASTM D1238 under a force of 21.6 kg.

In an aspect, the IMW component of polyethylene resin B can have aweight average molecular weight (M_(w)) of from about 85 kg/mol to about350 kg/mol.

In an aspect, the weight average molecular weight (M_(w)) of the IMWcomponent of polyethylene resin B can be greater than the weight averagemolecular weight (M_(w)) of the LMW component of polyethylene resin B.

In an aspect, the IMW component of polyethylene resin B can have anumber average molecular weight (M_(n)) of from about 10 kg/mol to about185 kg/mol; alternatively, from about 10 kg/mol to about 100 kg/mol;alternatively, from about 10 kg/mol to about 35 kg/mol.

In an aspect, the IMW component of polyethylene resin B can have az-average molecular weight (M_(z)) of from about 215 kg/mol to about2,300 kg/mol.

In an aspect, the IMW component of polyethylene resin B can have apolydispersity index (dispersity or PDI or M_(w)/M_(n)) of from about2.5 to about 35; alternatively, from about 2.5 to about 25.

In an aspect, the IMW component of polyethylene resin B can have a shortchain branching content of from about 0.1 to about 10 short chainbranches per 1,000 carbon atoms; alternatively, from about 0.1 to about8 short chain branches per 1,000 carbon atoms; alternatively, from about0.2 to about 7 short chain branches per 1,000 carbon atoms;alternatively, from about 0.3 to about 6 short chain branches per 1,000carbon atoms; alternatively, from about 0.4 to about 5 short chainbranches per 1,000 carbon atoms.

In an aspect, the HMW component of polyethylene resin B can be acopolymer.

In an aspect, the HMW component of polyethylene resin B can have acomonomer content of greater than about 0 wt. % to about 10 wt. %;alternatively, from about 1 wt. % to about 10 wt. %.

In an aspect, the comonomer content in the HMW component of polyethyleneresin B can be greater than the comonomer content of the IMW componentof polyethylene resin B.

In an aspect, the HMW component of polyethylene resin B can have adensity of from equal to or greater than about 0.900 g/cc to about 0.960g/cc; alternatively, from equal to or greater than about 0.900 g/cc toabout 0.940 g/cc; or alternatively, from equal to or greater than about0.900 g/cc to about 0.930 g/cc, when tested in accordance with ASTMD1505.

In an aspect, the HMW component can have a melt index (MI₂) of less thanabout 0.1 g/10 min, when tested in accordance with ASTM D1238 under aforce of 2.16 kg.

In an aspect, the HMW component of polyethylene resin B can have a highload melt index (HLMI) of from about 0.005 g/10 min to about 2 g/10 min,when tested in accordance with ASTM D1238 under a force of 21.6 kg.

In an aspect, the HMW component of polyethylene resin B can have weightaverage molecular weight (M_(w)) of greater than about 350 kg/mol;alternatively, from greater than about 350 kg/mol to about 1,500 kg/mol.

In an aspect, the HMW component of polyethylene resin B can have anumber average molecular weight (M_(n)) of from about 75 kg/mol to about200 kg/mol.

In an aspect, the HMW component of polyethylene resin B can have az-average molecular weight (M_(z)) of from about 1,700 kg/mol to about4,600 kg/mol.

In an aspect, the HMW component of polyethylene resin B can have apolydispersity index (dispersity or PDI or M_(w)/M_(n)) of from about 2to about 20; alternatively, from about 2 to about 15.

In an aspect, the HMW component of polyethylene resin B can have a shortchain branching content of from about 1 to about 15 short chain branchesper 1,000 carbon atoms; alternatively, from about 2 to about 13 shortchain branches per 1,000 carbon atoms; alternatively, from about 3 toabout 12 short chain branches per 1,000 carbon atoms; alternatively,from about 4 to about 11 short chain branches per 1,000 carbon atoms;alternatively, from about 5 to about 10 short chain branches per 1,000carbon atoms.

In an aspect, polyethylene resin B can have a Young's modulus (E) ofequal to or greater than about 900 MPa; alternatively from about 900 MPato about 1350 MPa, when tested in accordance with ASTM D638.

In an aspect, polyethylene resin B can have a tensile yield stress ofequal to or greater than about 20 MPa; alternatively, from about 20 MPato about 30 MPa, when tested in accordance with ASTM D638.

In an aspect, polyethylene resin B can have a tensile yield strain offrom about 5% to about 25%, when tested in accordance with ASTM D638.

In an aspect, polyethylene resin B can have a tensile natural draw ratioat room temperature of from about 300% to about 600%, when tested inaccordance with ASTM D638.

In an aspect, polyethylene resin B can have a tensile natural draw ratioat 80° C. of less than 500%; alternatively, of less than about 400%;alternatively, from about 250% to about 400%; alternatively, less thanabout 300%, when tested in accordance with ASTM D638.

In an aspect, polyethylene resin B can have a strain hardening modulusof from about 50 MPa to about 90 MPa, when tested in accordance with ISO18488-2015(E).

In an aspect, polyethylene resin B can have an environmental stresscracking resistance (ESCR) of equal to or greater than about 1,000hours, when tested in accordance with ASTM D1693 (condition A).

In an aspect, polyethylene resin B can have a resistance to slow crackgrowth of equal to or greater than about 800 h; alternatively, equal toor greater than about 2,000 h; alternatively, equal to or greater thanabout 5,000 h; or alternatively, equal to or greater than about 10,000h, when tested in accordance with ASTM F1473, with the caveat that theresistance to slow crack growth is defined as the polyethylene notchtensile test (PENT) failure time.

In an aspect, polyethylene resin B can have a resistance to slow crackgrowth of equal to or greater than about 8,760 h; alternatively, equalto or greater than about 10,000 h; alternatively, equal to or greaterthan about 15,000 h; alternatively, equal to or greater than about25,000 h; alternatively, equal to or greater than about 50,000 h;alternatively, equal to or greater than about 100,000 h; oralternatively, equal to or greater than about 500,000 h, when tested inaccordance with ISO 16770 at 80° C. and 6 MPa, with the caveat that theresistance to slow crack growth is defined as the full notch creep test(FNCT) failure time.

In an aspect, polyethylene resin B can have a resistance to slow crackgrowth of equal to or greater than about 100 h; alternatively, equal toor greater than about 500 h; alternatively, equal to or greater thanabout 1,000 h; alternatively, equal to or greater than about 5,000 h;alternatively, equal to or greater than about 10,000 h; oralternatively, equal to or greater than about 15,000 h, when tested inaccordance with ISO 13479:2009(E) at 4.6 MPa, with the caveat that theresistance to slow crack growth is defined as the notched pipe test(NPT) failure time.

In an aspect, polyethylene resin B can have a viscous relaxation time offrom about 0.5 s to about 7.5 s.

In an aspect, polyethylene resin B can have an η₀ (eta_0) of equal to orgreater than about 0.7×10⁵ Pa-s; alternatively, equal to or greater thanabout 1.0×10⁵ Pa-s; alternatively from about 0.7×10⁵ Pa-s to about2.0×10⁶ Pa-s.

In an aspect, polyethylene resin B can have an η₂₅₁ (eta_251) of lessthan about 1.5×10³ Pa-s.

In an aspect, polyethylene resin B can have a storage modulus (G′) offrom about 225,000 Pa to about 325,000 Pa, wherein G′ is measured at190° C. and 251 rad/s in accordance with ASTM D4440.

In an aspect, polyethylene resin B can have a loss modulus (G″) of fromabout 100,000 Pa to about 200.00 Pa, wherein G″ is measured at 190° C.and 251 rad/s in accordance with ASTM D4440.

In an aspect, polyethylene resin B can have a tan δ of from about 0.3 toabout 0.7; wherein tan δ is the ratio of the loss modulus (G″) tostorage modulus (G′), wherein G″ and G′ are measured at 190° C. and 251rad/s in accordance with ASTM D4440.

In an aspect, polyethylene resin B can be suitable for use as a film, apipe, or an article formed by blow molding, small part blow molding,large part blow molding, extrusion molding, rotational molding,thermoforming, cast molding, and the like.

In an aspect, polyethylene resin B can have a gel count of less thanabout 950 gels/m². Alternatively, polyethylene resin B can have a gelcount of less than about 900 gels/m²; alternatively, less than about 850gels/m²; alternatively, less than about 800 gels/m²; alternatively, lessthan about 750 gels/m²; alternatively, a gel count of less than about700 gels/m²; alternatively, less than about 650 gels/m²; alternatively,less than about 600 gels/m².

In an aspect, polyethylene resin B can be made by an embodiment of theprocess having a combination of the aspects described herein.

In an aspect, an amount of from about 40 to about 60 wt. % ofpolyethylene resin C can comprise the first polyolefin, an amount offrom about 5 to about 15 wt. % of polyethylene resin C can comprise thesecond polyolefin, and an amount of from about 30 to about 50 wt. % ofpolyethylene resin C can comprise the third polyolefin. Stated anotherway, an amount of from about 40 to about 60 wt. % of polyethylene resinC can comprise the LMW component, an amount of from about 5 to about 15wt. % of polyethylene resin C can comprise the IMW component, and anamount of from about 30 to about 50 wt. % of polyethylene resin C cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin C can present in an amount of from about 40 wt. % toabout 60 wt. %, the IMW component of polyethylene resin C can be presentin an amount of from about 5 wt. % to about 15 wt. %, and the HMWcomponent of polyethylene resin C can be present in an amount of fromabout 30 wt. % to about 50 wt. %.

In aspect, an amount of from about 40 to about 60 wt. % of polyethyleneresin C can comprise the first polyolefin, an amount of from about 5 toabout 35 wt. % of polyethylene resin C can comprise the secondpolyolefin, and an amount of from about 15 to about 50 wt. % ofpolyethylene resin C can comprise the third polyolefin. Stated anotherway, an amount of from about 40 to about 60 wt. % of polyethylene resinC can comprise the LMW component, an amount of from about 5 to about 35wt. % of polyethylene resin C can comprise the IMW component, and anamount of from about 15 to about 50 wt. % of polyethylene resin C cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin C can be present in an amount of from about 40 wt. %to about 60 wt. %, the IMW component of polyethylene resin C can bepresent in an amount of from about 5 wt. % to about 35 wt. %, and theHMW component of polyethylene resin C can be present in an amount offrom about 15 wt. % to about 50 wt. %.

In aspect, an amount of from about 50 wt. % of polyethylene resin C cancomprise the first polyolefin, an amount of from about 30 wt. % ofpolyethylene resin C can comprise the second polyolefin, and an amountof from about 20 wt. % of polyethylene resin C can comprise the thirdpolyolefin. Stated another way, an amount of from about 50 wt. % ofpolyethylene resin C can comprise the LMW component, an amount of fromabout 30 wt. % of polyethylene resin C can comprise the IMW component,and an amount of from about 20 wt. % of polyethylene resin C cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin C can be present in an amount of from about 50 wt. %,the IMW component of polyethylene resin C can be present in an amount offrom about 30 wt. %, and the HMW component of polyethylene resin C canbe present in an amount of from about 20 wt. %.

In an aspect, polyethylene resin C can be a copolymer formed using acomonomer in at least one of the first reactor 100 and the MZCR 300. Thecopolymer can have a comonomer content of from greater than about 0 wt.% to about 20 wt. %; alternatively, from greater than about 0 wt. % toabout 6 wt. %; alternatively, from about 2 wt. % to about 6 wt. %;alternatively, from about 1 wt. % to about 5 wt. %; alternatively, fromgreater than about 6 wt. % to about 20 wt. %; alternatively, fromgreater than about 6 wt. % to about 15 wt. %; or alternatively, fromgreater than about 6 wt. % to about 10 wt. %.

In an aspect, the LMW component of polyethylene resin C can have aweight average molecular weight (M_(w)) of from about 25 kg/mol to about65 kg/mol.

In an aspect, the IMW component of polyethylene resin C can have aweight average molecular weight (M_(w)) of from about 100 kg/mol toabout 200 kg/mol.

In an aspect, the weight average molecular weight (M_(w)) of the HMWcomponent of polyethylene resin C can be greater than the weight averagemolecular weight (M_(w)) of the IMW component of polyethylene resin C.

In an aspect, the HMW component of polyethylene resin C can have aweight average molecular weight (M_(w)) of from about 400 kg/mol toabout 925 kg/mol.

In an aspect, the LMW component of polyethylene resin C can have a shortchain branching content of from about 0 to about 2 short chain branchesper 1,000 carbon atoms.

In an aspect, the IMW component of polyethylene resin C can have a shortchain branching content of from about 0.1 to about 5 short chainbranches per 1,000 carbon atoms.

In an aspect, the HMW component of polyethylene resin C can have a shortchain branching content of from about 2 to about 12 short chain branchesper 1,000 carbon atoms.

In an aspect, polyethylene resin C can have a slow crack growth, and aresistance to slow crack growth can be of equal to or greater than about3,000 h, when tested in accordance with ASTM F1473, with the caveat thatresistance to slow crack growth is defined as the polyethylene notchtensile test (PENT) failure time.

In an aspect, polyethylene resin C can be a trimodal polyethylene resin.

In an aspect, polyethylene resin C can have a resistance to slow crackgrowth of equal to or greater than about 8,760 h, when tested inaccordance with ISO 16770 at 80° C. and 6 MPa, with the caveat that theresistance to slow crack growth is defined as the full notch creep test(FNCT) failure time.

In an aspect, polyethylene resin C can have a resistance to slow crackgrowth of equal to or greater than about 1,000 h, when tested inaccordance with ISO 13479:2009(E) at 4.6 MPa, wherein the resistance toslow crack growth is defined as the notched pipe test (NPT) failuretime.

In an aspect, polyethylene resin C can have a weight average molecularweight (M_(w)) of from about 200 kg/mol to about 400 kg/mol.

In an aspect, polyethylene resin C can have a number average molecularweight (M_(n)) of from about 7.5 kg/mol to about 20 kg/mol.

In an aspect, polyethylene resin C can have a z-average molecular weight(M_(z)) of from about 1,000 kg/mol to about 3,300 kg/mol.

In an aspect, polyethylene resin C can have an 7 o (eta_0) of equal toor greater than about 1.0×10⁵ Pa-s.

In an aspect, polyethylene resin C can be formed into a pipe.Additionally, polyethylene resin C can be suitable for use as a film oran article formed by blow molding, small part blow molding, large partblow molding, extrusion molding, rotational molding, thermoforming, castmolding, and the like.

In an aspect, polyethylene resin C can have a gel count of less thanabout 750 gels/m². Alternatively, polyethylene resin C can have a gelcount of less than about 700 gels/m²; alternatively, less than about 650gels/m²; alternatively, less than about 600 gels/m².

In an aspect, polyethylene resin C can be made by an embodiment of theprocess having a combination of the aspects described herein.

In an aspect, an amount of from about 40 to about 60 wt. % ofpolyethylene resin D can comprise the first polyolefin, an amount offrom about 5 to about 15 wt. % of polyethylene resin D can comprise thesecond polyolefin, and an amount of from about 30 to about 50 wt. % ofpolyethylene resin D can comprise the third polyolefin. Stated anotherway, an amount of from about 40 to about 60 wt. % of polyethylene resinD can comprise the LMW component, an amount of from about 5 to about 15wt. % of polyethylene resin D can comprise the IMW component, and anamount of from about 30 to about 50 wt. % of polyethylene resin D cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin D can present in an amount of from about 40 wt. % toabout 60 wt. %, the IMW component of polyethylene resin D can be presentin an amount of from about 5 wt. % to about 15 wt. %, and the HMWcomponent of polyethylene resin D can be present in an amount of fromabout 30 wt. % to about 50 wt. %.

In aspect, an amount of from about 40 to about 60 wt. % of polyethyleneresin D can comprise the first polyolefin, an amount of from about 5 toabout 35 wt. % of polyethylene resin D can comprise the secondpolyolefin, and an amount of from about 15 to about 50 wt. % ofpolyethylene resin D can comprise the third polyolefin. Stated anotherway, an amount of from about 40 to about 60 wt. % of polyethylene resinD can comprise the LMW component, an amount of from about 5 to about 35wt. % of polyethylene resin D can comprise the IMW component, and anamount of from about 15 to about 50 wt. % of polyethylene resin D cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin D can be present in an amount of from about 40 wt. %to about 60 wt. %, the IMW component of polyethylene resin D can bepresent in an amount of from about 5 wt. % to about 35 wt. %, and theHMW component of polyethylene resin D can be present in an amount offrom about 15 wt. % to about 50 wt. %.

In aspect, an amount of from about 50 wt. % of polyethylene resin D cancomprise the first polyolefin, an amount of from about 30 wt. % ofpolyethylene resin D can comprise the second polyolefin, and an amountof from about 20 wt. % of polyethylene resin D can comprise the thirdpolyolefin. Stated another way, an amount of from about 50 wt. % ofpolyethylene resin D can comprise the LMW component, an amount of fromabout 30 wt. % of polyethylene resin D can comprise the IMW component,and an amount of from about 20 wt. % of polyethylene resin D cancomprise the HMW component. Stated another way, the LMW component ofpolyethylene resin D can be present in an amount of from about 50 wt. %,the IMW component of polyethylene resin D can be present in an amount offrom about 30 wt. %, and the HMW component of polyethylene resin D canbe present in an amount of from about 20 wt. %.

In an aspect, polyethylene resin D can be a copolymer formed using acomonomer in at least one of the first reactor 100 and the MZCR 300. Thecopolymer can have a comonomer content of from greater than about 0 wt.% to about 20 wt. %; alternatively, from greater than about 0 wt. % toabout 6 wt. %; alternatively, from about 2 wt. % to about 6 wt. %;alternatively, from about 1 wt. % to about 5 wt. %; alternatively, fromgreater than about 6 wt. % to about 20 wt. %; alternatively, fromgreater than about 6 wt. % to about 15 wt. %; or alternatively, fromgreater than about 6 wt. % to about 10 wt. %.

In an aspect, the LMW component of polyethylene resin D can have aweight average molecular weight (M_(w)) of from about 30 kg/mol to about50 kg/mol.

In an aspect, the IMW component of polyethylene resin D can have aweight average molecular weight (M_(w)) of from about 90 kg/mol to about150 kg/mol.

In an aspect, the HMW component of polyethylene resin D can have aweight average molecular weight (M_(w)) of from about 450 kg/mol toabout 750 kg/mol.

In an aspect, the LMW component of polyethylene resin D can have a shortchain branching content of from about 0.1 to about 2 short chainbranches per 1,000 carbon atoms.

In an aspect, the IMW component of polyethylene resin D can have a shortchain branching content of from about 0.1 to about 5 short chainbranches per 1,000 carbon atoms.

In an aspect, the HMW component of polyethylene resin D can have a shortchain branching content of from about 2 to about 10 short chain branchesper 1,000 carbon atoms.

In an aspect, polyethylene resin D can have a tensile strength in themachine direction (MD) of greater than about 13,000 psi (about 89.6MPa), when tested in accordance with ASTM D638 at 90 MPa.

In an aspect, polyethylene resin D can be a trimodal polyethylene resin.

In an aspect, polyethylene resin D can have a tensile strength in thetransverse direction (TD) of greater than about 6,000 psi (about 41.4MPa), when tested in accordance with ASTM D638 at 41 MPa.

In an aspect, polyethylene resin D can have an η₀ (eta_0) of equal to orgreater than about 1.0×10⁵ Pa-s.

In an aspect, polyethylene resin D can be formed into a film.Additionally, polyethylene resin D can be suitable for use as a pipe oran article formed by blow molding, small part blow molding, large partblow molding, extrusion molding, rotational molding, thermoforming, castmolding, and the like.

In an aspect, polyethylene resin D can be made by an embodiment of theprocess having a combination of the aspects described herein.

In an aspect, the multimodal polyolefin is a polyethylene resin E madeby an embodiment of the process having a combination of the aspectsdescribed herein.

In an aspect, polyethylene resin E can be suitable for use as a pipe,film, or an article formed by blow molding, small part blow molding,large part blow molding, extrusion molding, rotational molding,thermoforming, cast molding, and the like.

In an aspect, polyethylene resin E can be a trimodal polyethylene resin.

In an aspect, polyethylene resin E can be a copolymer formed using acomonomer in at least one of the first reactor 100 and the MZCR 300. Thecopolymer can have a comonomer content of from greater than about 0 wt.% to about 20 wt. %; alternatively, from greater than about 0 wt. % toabout 6 wt. %; alternatively, from about 2 wt. % to about 6 wt. %;alternatively, from about 1 wt. % to about 5 wt. %; alternatively, fromgreater than about 6 wt. % to about 20 wt. %; alternatively, fromgreater than about 6 wt. % to about 15 wt. %; or alternatively, fromgreater than about 6 wt. % to about 10 wt. %.

In an aspect, the multimodal polyolefin that is a polyethylene resin A,B, C, D, or E can be produced using Ziegler-Natta catalyst in each ofpolymerization zones 112, 321, and 341. Stated another way, themultimodal polyolefin that is a polyethylene resin A, B, C, D, or E canbe produced using Ziegler-Natta catalyst in each of the first reactor100, the riser 320 of the MZCR 300, and the downcomer 340 of the MZCR300. Put yet another way, the multimodal polyolefin that is apolyethylene resin A, B, C, D, or E can be produced using Ziegler-Nattacatalyst in each of the first reactor 100 and the MZCR 300.

In an aspect, the LMW component of the multimodal polyolefin that ispolyethylene resin A, B, C, D, or E can be produced in a polymerizationzone 112 in the substantial absence of any comonomer described herein.Stated another way, the LMW component of the multimodal polyolefin thatis polyethylene resin A, B, C, D, or E can be produced in the firstreactor 100 in the substantial absence of any comonomer describedherein.

In an aspect, the IMW component of the multimodal polyolefin that ispolyethylene resin A, B, C, D, or E can be produced in polymerizationzone 321 in the presence of a comonomer and hydrogen. Stated anotherway, the IMW component of the multimodal polyolefin that is polyethyleneresin A, B, C, D, or E can be produced in the riser 320 of the MZCR 300in the presence of a comonomer and hydrogen.

In an aspect, the HMW component of the multimodal polyolefin that ispolyethylene resin A, B, C, D, or E can be produced in a polymerizationzone 341 in the presence of a comonomer and hydrogen. Stated anotherway, the HMW component of the multimodal polyolefin that is polyethyleneresin A, B, C, D, or E can be produced in the downcomer 340 of the MZCR300 in the presence of a comonomer and hydrogen.

In an aspect, the amount of comonomer used in the polymerization zone341 is greater than the amount of comonomer used in the polymerizationzone 321. Stated another way, the amount of comonomer used in thedowncomer 340 of the MZCR 300 is greater than the amount of comonomerused in the riser 320 of the MZCR 300.

In an aspect, the amount of hydrogen used in the polymerization zone 321is greater than the amount of hydrogen used in the polymerization zone341. Stated another way, the amount of hydrogen used in the riser 320 ofthe MZCR 300 is greater than the amount of hydrogen used in thedowncomer 340 of the MZCR 300.

In an aspect, any of polyethylene resins A, B, C, D, or E can have anη₂₅₁ (eta_251) of less than about 1.5×10³ Pa-s.

In an aspect, the first reactor 100 that produces the LMW component ofany of polyethylene resins A, B, C, D, or E can be a gas phase reactor(also referred to as fluidized bed reactor). Stated another way, thepolymerization zone 112 that produces the LMW component of any ofpolyethylene resins A, B, C, D, or E can be a gas phase reaction zone(also referred to as fluidized bed reaction zone).

In an aspect, the polymerization zone 321 of the MZCR 300 that producesthe IMW component of any of polyethylene resins A, B, C, D, or E is afast fluidization reaction zone. Stated another way, the polymerizationzone 321 of the MZCR 300 that produces the IMW component of any ofpolyethylene resins A, B, C, D, or E operates under fast fluidizationconditions. Stated another way, the riser 320 of the MZCR 300 thatproduces the IMW component of any of polyethylene resins A, B, C, D, orE operates under fast fluidization conditions.

In an aspect, the polymerization zone 341 of the MZCR 300 that producesthe HMW component of any of polyethylene resins A, B, C, D, or E is aplug flow reaction zone. Stated another way, the polymerization zone 341of the MZCR 300 that produces the HMW component of any of polyethyleneresins A, B, C, D, or E operates under plug flow conditions. Statedanother way, the downcomer 340 of the MZCR 300 that produces the HMWcomponent of any of polyethylene resins A, B, C, D, or E operates underplug flow conditions.

Additional Aspects

Apparatuses and processes for multiple reactor and multiple zonepolyolefin polymerization have been described. Described below areprocess A, process B, process C, process D, apparatus A, apparatus B,apparatus C, apparatus D, polyethylene resin A, polyethylene resin B,polyethylene resin C, polyethylene resin D, polyethylene resin E andpolyethylene resin F.

A first aspect of process A, which is a process for producing amultimodal polyolefin, is that process A comprises (a) polymerizingethylene in a first reactor to produce a first polyolefin, (b)polymerizing ethylene in a first reaction mixture in a riser of a secondreactor to produce a second polyolefin, (c) passing the first reactionmixture through an upper conduit from the riser to a separator, (d)recovering, in the separator, the second polyolefin from the firstreaction mixture, (e) passing the second polyolefin from the separatorinto a downcomer of the second reactor, optionally via a liquid barrier,(f) polymerizing ethylene in a second reaction mixture in the downcomerto produce a third polyolefin, (g) passing the second reaction mixturethrough a lower conduit from the downcomer to the riser, and (h) one of(1) after step (a) and before steps (b)-(g), receiving the firstpolyolefin into the second reactor, or (2) before step (a) and aftersteps (b)-(g), receiving the second polyolefin and the third polyolefininto the first reactor.

In a second aspect of process A which can be used in combination withthe first aspect of process A, the riser has a width-to-height ratio ofless than about 0.1.

In a third aspect of process A which can be used in combination with anyof the first to the second aspects of process A, the downcomer has awidth-to-height ratio of less than about 0.1.

In a fourth aspect of process A which can be used in combination withany of the first to the third aspects of process A, the upper conduithas a length-to-diameter ratio of about 5 to about 20.

In a fifth aspect of process A which can be used in combination with anyof the first to the fourth aspects of process A, the lower conduit has alength-to-diameter ratio of about 5 to about 20.

In a sixth aspect of process A which can be used in combination with anyof the first to the fifth aspects of process A, process A furthercomprises adding or removing heat from the riser.

In a seventh aspect of process A which can be used in combination withany of the first to the sixth aspects of process A, process A furthercomprises adding or removing heat from the downcomer.

In an eighth aspect of process A which can be used in combination withany of the first to the seventh aspects of process A, the second reactorfurther comprises a transition conduit fluidly connected to the end ofthe lower conduit.

In a ninth aspect of process A which can be used in combination with theeighth aspect of process A, an angle of the transition conduit withrespect to horizontal is less than about 90°.

In a tenth aspect of process A which can be used in combination with anyof the eighth through the ninth aspects of process A, a length of thetransition conduit is from about 6 feet to about 15 feet.

In an eleventh aspect of process A which can be used in combination withany of the eighth through the tenth aspects of process A, the secondreactor further comprises a first elbow connector connected to a bottomportion of the riser and to an end of the lower conduit, and a secondelbow connector connected to a top portion of the riser and to an end ofthe upper conduit, an a tee connector having a first connecting portionconnected a bottom section of the downcomer, a second connecting portionconnected to the lower conduit, and a third end connected to an end ofthe transition conduit, wherein a first angle between the first end andthe second end is equal to or less than about 90° and a second anglebetween the second end and the third end is equal to or greater than90°.

In a twelfth aspect of process A which can be used in combination withany of the first to the eleventh aspects of process A, the secondreactor further comprises a first elbow connector connected to a bottomportion of the riser and to an end of the lower conduit, and a secondelbow connector connected to a top portion of the riser and to an end ofthe upper conduit, and a third elbow connector connected to a bottomportion of the downcomer and to another end of the lower conduit.

In a thirteen aspect of process A which can be used in combination withthe twelfth aspect of process A, at least one of the first, the second,or the third elbow connector has an inner diameter (d) and a radius(R_(c)) of an inner curvature, and process A further comprisesmaintaining, by at least one of the first, the second, or the thirdelbow, a Dean number (D_(n)) of the first or second reaction mixtureflowing therein to be higher than 3,000,000, whereD_(n)=ρVd/μ*(d/2R_(c))^(1/2) and wherein ρ is a density of the first orsecond reaction mixture, V is a circulation velocity of the first orsecond reaction mixture, and μ is a dynamic viscosity of the first orsecond reaction mixture.

In a fourteenth aspect of process A which can be used in combinationwith any of the first to the thirteen aspects of process A, process Afurther comprises an elbow connector connected i) to the bottom portionof the riser and to the opposite end of the lower conduit, ii) to thetop portion of the riser and to the end of the upper conduit, or iii) tothe bottom portion of the downcomer and to the end of the lower conduit,wherein the elbow connector comprises a first tap on an outside radiusof the elbow connector, a second tap on an inside radius of the elbowconnector, a first sensing leg coupling the first tap to a differentialpressure meter, and a second sensing leg coupling the second tap to thedifferential pressure meter.

In a fifteenth aspect of process A which can be used in combination withany of the first to the fourteenth aspects of process A, the secondreactor has an internal surface which is polished to a root mean squareof less than about 3.8 microns (150 microinches).

In a sixteenth aspect of process A which can be used in combination withany of the first to the fifteenth aspects of process A, an internalsurface of the first reactor or an internal surface of the secondreactor has a rust inhibitor coating.

In a seventeenth aspect of process A which can be used in combinationwith any of the first to the sixteenth aspects of process A, at least aportion of the first reactor or at least a portion of the second reactoris made of carbon steel, stainless steel, or a combination thereof.

In an eighteenth aspect of process A which can be used in combinationwith any of the first to the seventeenth aspects of process A, at leasta portion of the first reactor or at least a portion of the secondreactor is made of carbon steel, wherein the carbon steel is a lowtemperature carbon steel.

In a nineteenth aspect of process A which can be used in combinationwith any of the first to the eighteenth aspects of process A, one ormore thermowells are located on the second reactor.

In a twentieth aspect of process A which can be used in combination withany of the first to the nineteenth aspects of process A, the secondreactor further comprises an eductor or a standpipe coupled to the lowerconduit or to a transition conduit fluidly connected to an end of thelower conduit.

In a twenty-first aspect of process A which can be used in combinationwith any of the first to the twentieth aspects of process A, the secondreactor further comprises a gas density meter configured to measure adensity of the first reaction mixture in the riser.

In a twenty-second aspect of process A which can be used in combinationwith any of the first to the twenty-first aspects of process A, thefirst polyolefin is a lower molecular weight polyethylene, the thirdpolyolefin is a higher molecular weight polyethylene.

In a twenty-third aspect of process A which can be used in combinationwith the twenty-second aspect of process A, the second polyolefin has anaverage molecular weight greater (M_(w), M_(n), or M_(z)) than anaverage molecular weight (M_(w), M_(n), or M_(z)) of the firstpolyolefin and less than an average molecular weight of the thirdpolyolefin.

In a twenty-fourth aspect of process A which can be used in combinationwith any of the first to the twenty-third aspects of process A, fromabout 20 to about 80 wt. % of the multimodal polyolefin comprises thefirst polyolefin and from about 80 to about 20 wt. % of the multimodalpolyolefin comprises the second polyolefin and the third polyolefin.

In a twenty-fifth aspect of process A which can be used in combinationwith any of the first to the twenty-fourth aspects of process A, themultimodal polyolefin has a density in a range of from about 0.930 toabout 0.970 g/ml when tested in accordance with ASTM D1505, a melt indexin a range of from about 0.1 to about 30 g/10 min when tested inaccordance with ASTM D1238 under a force of 2.16 kg and a temperature of190° C., a comonomer content in a range of from 0 to about 6 wt. %, anda M_(w) in a range of from about 250 to about 1,500 kg/mol.

In a twenty-sixth aspect of process A which can be used in combinationwith the twenty-fifth aspect of process A, the multimodal polyolefin hasa high load melt index of from about 1 to about 45 g/10 min when testedin accordance with ASTM D1238 under a force of 21.6 kg and a temperatureof 190° C., a M_(z) in a range of from about 500 to about 5,000 kg/mol,a Mw/Mn in a range of from about 18 to about 52, a long chain branchingindex in a range of from 0 to about 0.96, and a shear inducedcrystallization (SIC) index in a range of from about 0.15 to about 8.

In a twenty-seventh aspect of process A which can be used in combinationwith any of the first to the twenty-sixth aspects of process A, thefirst reactor is a loop slurry reactor, a fluidized bed reactor, anautoclave reactor, a tubular reactor, a horizontal gas phase reactor, acontinuous stirred-tank reactor, or a solution reactor.

A first aspect of process B, which is a process for producing amultimodal polyolefin, is that process B comprises (a) polymerizingethylene in a first reactor to produce a first polyolefin, (b)polymerizing ethylene in a first reaction mixture in a riser of a secondreactor to produce a second polyolefin contained in a riser productmixture, (c) passing the riser product mixture through an upper conduitfrom the riser to a separator, (d) recovering, in the separator, thesecond polyolefin from the riser product mixture, (e) passing the secondpolyolefin from the separator into a downcomer of the second reactor,optionally via a liquid barrier, (f) polymerizing ethylene in a secondreaction mixture in the downcomer to produce a third polyolefin in adowncomer product mixture, (g) passing the downcomer product mixturethrough a lower conduit from the downcomer to the riser, and (h) one of(1) after step (a) and before steps (b)-(g), receiving the firstpolyolefin into the second reactor, or (2) before step (a) and aftersteps (b)-(g), receiving the second polyolefin and the third polyolefininto the first reactor.

In a second aspect of process B which can be used in combination withthe first aspect of process B, process B further comprises discharging aportion of the downcomer product mixture containing the multimodalpolyolefin from the downcomer of the second reactor.

In a third aspect of process B which can be used in combination with anyof the first to the second aspects of process B, the downcomer productmixture is discharged through a product discharge conduit that isfluidly connected to the downcomer i) on a bottom half of the downcomeror ii) on or near a bottom tangent of the downcomer, wherein the productdischarge conduit is fluidly connected to a continuous take-off valve ora discontinuous take-off valve.

In a fourth aspect of process B which can be used in combination withany of the first to the third aspects of process B, the productdischarge conduit is connected to the downcomer such that an angle ofthe product discharge conduit with respect to horizontal is from about−60° to about 60°.

In a fifth aspect of process B which can be used in combination with anyof the first to the fourth aspects of process B, process B furthercomprises passing the portion of the downcomer product mixture through aheater, wherein the heater is coupled to the product discharge conduit.

In a sixth aspect of process B which can be used in combination with thefifth aspect of process B, process B further comprises adding a catalystor cocatalyst poison or deactivator to the downcomer product mixture inor upstream of the heater.

In a seventh aspect of process B which can be used in combination withany of the first to the sixth aspects of process B, process B furthercomprises discharging a polymer product in the downcomer product mixturefrom the heater at a temperature i) of from about 54.4° C. (130° F.) toabout 104.4° C. (220° F.), or ii) below a melting point of the polymerproduct.

In an eighth aspect of process B which can be used in combination withany of the first to the seventh aspects of process B, process B furthercomprises receiving the downcomer product mixture from the heater into aseparation vessel, and separating, in the separation vessel, thedowncomer product mixture into a plurality of streams, each of theplurality of streams comprising a vapor, a polymer product, or both thevapor and the polymer product.

In a ninth aspect of process B which can be used in combination with theeighth aspect of process B, process B further comprises recovering oneor more of an olefin monomer, an olefin comonomer, and a diluent from atleast one of the plurality of streams comprising the vapor, andrecycling one or more of the olefin monomer, the olefin comonomer, andthe diluent to the first reactor, the second reactor, or both the firstreactor and the second reactor.

In a tenth aspect of process B which can be used in combination with anyof the first to the seventh aspects of process B, process B furthercomprises receiving the polymer product from the separation vessel intoa degassing vessel, and removing, in the degassing vessel, at least aportion of a hydrocarbon entrained within the polymer product.

In an eleventh aspect of process B which can be used in combination withany of the first to the tenth aspects of process B, process B furthercomprises discharging a product mixture containing the multimodalpolyolefin from the first reactor.

In a twelfth aspect of process B which can be used in combination withthe eleventh aspect of process B, the product mixture is dischargedthrough a product discharge conduit that is fluidly connected to thefirst reactor, wherein the product discharge conduit is fluidlyconnected to a continuous take-off valve or a discontinuous take-offvalve.

In a thirteenth aspect of process B which can be used in combinationwith the twelfth aspect of process B, the product discharge conduit isconnected to the first reactor such that an angle of the productdischarge conduit with respect to horizontal is from about −600° to 60°.

In a fourteenth aspect of process B which can be used in combinationwith any of the first to the thirteenth aspects of process B, process Bfurther comprises passing the product mixture through a heater, whereinthe heater is coupled to the product discharge conduit.

In a fifteenth aspect of process B which can be used in combination withthe fourteenth aspect of process B, process B further comprises adding acatalyst or cocatalyst poison or deactivator to the downcomer productmixture in or upstream of the heater.

In a sixteenth aspect of process B which can be used in combination withany of the first to the fifteenth aspects of process B, process Bfurther comprises discharging a polymer product in the product mixturefrom the heater at a temperature i) of from about 54.4° C. (130° F.) toabout 104.4° C. (220° F.), or ii) below a melting point of the polymerproduct.

In a seventeenth aspect of process B which can be used in combinationwith any of the first to the fifteenth aspects of process B, process Bfurther comprises receiving the product mixture from the heater into aseparation vessel, and separating, in the separation vessel, the productmixture into a plurality of streams, each of the plurality of streamscomprising a vapor, a polymer product, or both the vapor and the polymerproduct.

In an eighteenth aspect of process B which can be used in combinationwith the seventeenth aspect of process B, process B further comprisesrecovering one or more of an olefin monomer, an olefin comonomer, and adiluent from at least one of the plurality of streams comprising thevapor, and recycling one or more of the olefin monomer, the olefincomonomer, and the diluent to the first reactor, the second reactor, orboth the first reactor and the second reactor.

In a nineteenth aspect of process B which can be used in combinationwith any of the first to the eighteenth aspects of process B, process Bfurther comprises receiving the polymer product from the separationvessel into a degassing vessel, and removing, in the degassing vessel,at least a portion of a hydrocarbon entrained within the polymerproduct.

In a twentieth aspect of process B which can be used in combination withany of the first to the nineteenth aspects of process B, the separatorcomprises a cyclone separator.

In a twenty-first aspect of process B which can be used in combinationwith the twentieth aspect of process B, the cyclone separator is a highefficiency cyclone separator, and process B further comprisesseparating, by the cyclone separator, 99 wt. % or more of solidparticles in a riser product mixture from gas in the riser productmixture, wherein the solid particles have a size of about from about 2μm to about 10 μm.

In a twenty-second aspect of process B which can be used in combinationwith any of the first to the twenty-first aspects of process B, thecyclone separator has a cone angle with respect to horizontal of fromabout 45° to about 80°.

In a twenty-third aspect of process B which can be used in combinationwith any of the first to the twenty-second aspects of process B, thecyclone separator has a tangential entrance angle of from 0° to about15°.

In a twenty-fourth aspect of process B which can be used in combinationwith any of the first to the twenty-third aspects of process B, whereinthe riser product mixture in step (c) is passed into a tangentialentrance of the separator at a tangential entrance velocity of fromabout 15.24 m/s (50 ft/sec) to about 30.48 m/s (100 ft/sec).

In a twenty-fifth aspect of process B which can be used in combinationwith any of the first to the twenty-fourth aspects of process B, anangle with respect to horizontal of an opposite end of the upper conduitwhich fluidly connects to the cyclone separator is about 0° to about15°.

In a twenty-sixth aspect of process B which can be used in combinationwith any of the first to the twenty-fifth aspects of process B, anopposite end of the upper conduit connects to the cyclone separator at alocation of from about 0 m (0 ft) to about 6.10 m (20 ft) below a top ofthe cyclone separator.

In a twenty-seventh aspect of process B which can be used in combinationwith any of the first to the twenty-sixth aspects of process B, processB further comprises adding a reactor deactivation system to the secondreactor, wherein the reactor deactivation system is configured tomoderate or kill polymerization reactions in the riser, the downcomer,or both the riser and the downcomer.

In a twenty-eighth aspect of process B which can be used in combinationwith any of the first to the twenty-seventh aspects of process B, theseparator comprises a flash tank or a flash chamber.

In a twenty-ninth aspect of process B which can be used in combinationwith any of the first to the twenty-eighth aspects of process B, thefirst polyolefin is a lower molecular weight polyethylene, the thirdpolyolefin is a higher molecular weight polyethylene.

In a thirtieth aspect of process B which can be used in combination withthe twenty-ninth aspect of process B, the second polyolefin has anaverage molecular weight (M_(w), M_(n), or M_(z)) greater than anaverage molecular weight (M_(w), M_(n), or M_(z)) of the firstpolyolefin and less than an average molecular weight of the thirdpolyolefin.

In a thirty-first aspect of process B which can be used in combinationwith any of the first to the thirtieth aspects of process B, the firstreactor is a loop slurry reactor, a fluidized bed reactor, an autoclavereactor, a tubular reactor, a horizontal gas phase reactor, a continuousstirred-tank reactor, or a solution reactor.

In a thirty-second aspect of process B which can be used in combinationwith any of the first to the thirty-first aspects of process B, whereinfrom about 20 to about 80 wt. % of the multimodal polyolefin comprisesthe first polyolefin and from about 80 to about 20 wt. % of themultimodal polyolefin comprises the second polyolefin and the thirdpolyolefin.

In a thirty-third aspect of process B which can be used in combinationwith any of the first to the thirty-second aspects of process B, themultimodal polyolefin has a density in a range of from about 0.930 toabout 0.970 g/ml, a melt index in a range of from about 0.1 to about 30g/10 min when tested in accordance with ASTM D1238 under a force of 2.16kg and a temperature of 190° C., a comonomer content in a range of from0 to about 6 wt. %, and a M_(w) in a range of from about 250 to about1,500 kg/mol.

In a thirty-fourth aspect of process B which can be used in combinationwith the thirty-third aspect of process B, the multimodal polyolefin hasa high load melt index of from about 1 to about 45 g/10 min when testedin accordance with ASTM D1238 under a force of 21.6 kg and a temperatureof 190° C., a M_(z) in a range of from about 500 to about 5,000 kg/mol,a M_(w)/M_(n) in a range of from about 18 to about 52, a long chainbranching index in a range of from 0 to about 0.96, and a shear inducedcrystallization (SIC) index in a range of from about 0.15 from about 8.

A first aspect of process C, which is a process for producing amultimodal polyolefin, performed with i) a first reactor having a firstpolymerization zone, and ii) a second reactor having a secondpolymerization zone in a riser and a third polymerization zone in adowncomer, is that process C comprises (a) polymerizing ethylene in thefirst polymerization zone to produce a first polyolefin, (b) passing afirst reaction mixture upward through the second polymerization zone ofthe riser, wherein a second polyolefin is produced in the secondpolymerization zone, (c) receiving the first reaction mixture from thesecond polymerization zone in a separator, (d) separating, by theseparator, a first polyolefin product from the received first reactionmixture, (e) passing the first polyolefin product through a barriersection of the second reactor and into the third polymerization zone,(f) adding, in the third polymerization zone, the first polyolefinproduct to a second reaction mixture, (g) passing the second reactionmixture downward through the third polymerization zone of the downcomer,wherein a third polyolefin is produced in the third polymerization zone,(h) repeating steps (b)-(g) n times, wherein n=1 to 100,000 and (i) oneof 1) adding the first polyolefin to the second reactor at a locationupstream of the second polymerization zone with respect to a directionof flow of the first reaction mixture in the second polymerization zone,and withdrawing the multimodal polyolefin from the downcomer, or 2)withdrawing a portion of a second polyolefin product from the secondreactor, adding the portion of the second polyolefin product to thefirst polymerization zone of the first reactor, and withdrawing themultimodal polyolefin from the first reactor.

In a second aspect of process C which can be used in combination withthe first aspect of process C, a gas composition of the second reactionmixture is different than a gas composition of the third reactionmixture.

In a third aspect of process C which can be used in combination with anyof the first to the second aspects of process C, the gas composition ofthe second reaction mixture comprises at least two selected frommonomer, diluent, and a catalyst.

In a fourth aspect of process C which can be used in combination withany of the first to the third aspects of process C, the gas compositionof the third reaction mixture comprises at least two selected fromhydrogen, monomer, comonomer, diluent, and a catalyst.

In a fifth aspect of process C which can be used in combination with anyof the first to the fourth aspects of process C, wherein the barriersection is a liquid barrier comprising an inert liquid, wherein aconcentration of the inert liquid in the liquid barrier is greater thana concentration of the inert liquid in the second polymerization zoneand in the third polymerization zone.

In a sixth aspect of process C which can be used in combination with anyof the first to the fifth aspects of process C, process C furthercomprises injecting comonomer into the third polymerization zone via oneor more locations in the downcomer, wherein the third polyolefin is acopolymer.

In a seventh aspect of process C which can be used in combination withany of the first to the sixth aspects of process C, process C furthercomprises injecting an anti-static agent into one or more locations ofthe second reactor.

In an eighth aspect of process C which can be used in combination withthe seventh aspect of process C, the step of injecting an anti-staticagent comprises injecting a mixture comprising the anti-static agent anda carrier fluid into the one or more locations via one or moreanti-static agent feed lines, wherein a concentration of the anti-staticagent in each of the one or more anti-static agent feed lines is about 1ppm to about 50 ppm based on weight of the carrier fluid in each of theone or more anti-static agent feed lines.

In a ninth aspect of process C which can be used in combination with anyof the first to the eighth aspects of process C, a concentration of theanti-static agent in the second reactor is about 1 ppm to about 50 ppmbased on weight of the carrier fluid in the second reactor.

In a tenth aspect of process C which can be used in combination with anyof the first to the ninth aspects of process C, after passing the firstreaction mixture upward through the second polymerization zone of theriser and before receiving the first reaction mixture in the separator,the process further comprises flowing the first reaction mixture throughan upper conduit that fluidly connects the riser and the separator,wherein the first reaction mixture flows in the upper conduit at avelocity that is i) greater than a saltation velocity of the firstreaction mixture and up to about 30.48 m/s (100 ft/sec), or ii) greaterthan 110% of the saltation velocity of the first reaction mixture.

In an eleventh aspect of process C which can be used in combination withany of the first to the tenth aspects of process C, after passing thesecond reaction mixture downward through the third polymerization zoneof the downcomer, the process further comprises flowing the secondreaction mixture through a lower conduit that fluidly connects thedowncomer and the riser, wherein the second reaction mixture flows inthe lower conduit at a velocity that is i) greater than a saltationvelocity of the second reaction mixture and up to about 30.48 m/s (100ft/sec), or ii) greater than 110% of the saltation velocity of thesecond reaction mixture.

In a twelfth aspect of process C which can be used in combination withany of the first to the eleventh aspects of process C, process C furthercomprises analyzing a sample of the first reaction mixture or the secondreaction mixture at one or more locations in the second reactor todetermine a concentration of gas, liquid, or solid in the first reactionmixture or the second reaction mixture, and to determine a concentrationof monomer, comonomer, diluent, hydrogen, inert component, or polymer inthe first reaction mixture or the second reaction mixture.

In a thirteenth aspect of process C which can be used in combinationwith any of the first to the twelfth aspects of process C, process Cfurther comprises controlling a level of the first polyolefin product inthe separator such that the first polyolefin product has a residencetime of about 1 second to about 30 minutes in the separator.

In a fourteenth aspect of process C which can be used in combinationwith any of the first to the thirteenth aspects of process C, from about20 to about 80 wt. % of the multimodal polyolefin comprises the firstpolyolefin and from about 80 to about 20 wt. % of the multimodalpolyolefin comprises the second polyolefin and the third polyolefin.

In a fifteenth aspect of process C which can be used in combination withany of the first to the fourteenth aspects of process C, the multimodalpolyolefin has a density in a range of from about 0.930 to about 0.970g/ml when tested in accordance with ASTM D1505, a melt index in a rangeof from about 0.1 to about 30 g/10 min when tested in accordance withASTM D1238 under a force of 2.16 kg and a temperature of 190° C., acomonomer content in a range of from about 0 to about 6 wt. %, and aM_(w) in a range of from about 250 to about 1,500 kg/mol.

In a sixteenth aspect of process C which can be used in combination withthe fifteenth aspect of process C, the multimodal polyolefin has a highload melt index of from about 1 to about 45 g/10 min when tested inaccordance with ASTM D1238 under a force of 21.6 kg and a temperature of190° C., a M_(z) in a range of from about 500 to about 5,000 kg/mol, aMw/Mn in a range of from about 18 to about 52, a long chain branchingindex in a range of from 0 to about 0.96, and a shear inducedcrystallization (SIC) index in a range of from about 0.15 to about 8.

In a seventeenth aspect of process C which can be used in combinationwith any of the first to the sixteenth aspects of process C, the firstpolymerization zone is in a loop slurry reactor, a fluidized bedreactor, an autoclave reactor, a tubular reactor, a horizontal gas phasereactor, a continuous stirred-tank reactor, or a solution reactor.

In an eighteenth aspect of process C which can be used in combinationwith any of the first to the seventeenth aspects of process C, the Mw ofthe first polyolefin and the Mw of the third polyolefin differ by anamount of greater than 10%, wherein step (b) comprises passing the firstreaction mixture upward through the second polymerization zone of theriser such that an average residence time of the first reaction mixturein the second polymerization zone during a single pass is in a range ofabout 1 second to about 5 minutes.

In a nineteenth aspect of process C which can be used in combinationwith any of the fifteenth aspect or the eighteenth aspect of process C,the Mw of the first polyolefin and the Mw of the third polyolefin differby an amount of greater than 10%, wherein step (g) comprises passing thesecond reaction mixture downward through the third polymerization zoneof the downcomer such that an average residence time of the secondreaction mixture in the third polymerization zone during a single passis in a range of about 5 seconds to about 15 minutes.

In a twentieth aspect of process C which can be used in combination withany of the eighteenth aspect or the nineteenth aspect of process C, step(a) comprises polymerizing the first polyolefin in the firstpolymerization zone such that an average residence time of the firstpolyolefin in the first polymerization zone is in a range of about 1second to about 14 hours; alternatively, about 1 second to about 12hours; alternatively, about 1 second to about 10 hours; alternatively,about 1 second to about 8 hours; alternatively, about 2 hours to about14 hours; alternatively, about 4 hours to about 14 hours; alternatively,about 4 hours to about 12 hours; alternatively, from about 1 hour toabout 3 hours; alternatively, about 1 second to about 5 minutes;alternatively, less than 10 hours; alternatively, greater than 1 hour.

A first aspect of process D, which is a process for producing amultimodal polyolefin, is that process D comprises (a) polymerizingethylene in a first reactor to produce a first polyolefin, (b)polymerizing ethylene in a first reaction mixture in a riser of a secondreactor to produce a second polyolefin, (c) passing the first reactionmixture through an upper conduit from the riser to a separator, (d)recovering, in the separator, the second polyolefin from the firstreaction mixture, (e) passing the second polyolefin from the separatorinto a downcomer of the second reactor, optionally via a liquid barrier,(f) polymerizing ethylene in a second reaction mixture in the downcomerto produce a third polyolefin, (g) passing the second reaction mixturethrough a lower conduit from the downcomer to the riser, and (h) one of(1) after step (a) and before steps (b)-(g), receiving the firstpolyolefin from the first reactor into the second reactor; or (2) beforestep (a) and after steps (b)-(g), receiving the second polyolefin andthe third polyolefin from the second reactor into the first reactor.

In a second aspect of process D which can be used in combination withthe first aspect of process D, the first reactor is a fluidized bedreactor, wherein receiving the first polyolefin from the first reactorinto the second reactor comprises receiving the first polyolefin into asettling leg placed at least partially within a bottom portion of thefluidized bed reactor, wherein an end of the settling leg opens to thegas distributor and an opposite end extends outside the fluidized bedreactor.

In a third aspect of process D which can be used in combination with anyof the first to the second aspects of process D, the settling leg has aninner diameter of from about 10.16 cm (4 inches) to about 30.48 cm (12inches).

In a fourth aspect of process D which can be used in combination withany of the first to the third aspects of process D, process D furthercomprises receiving the first polyolefin and a gas mixture from thesettling leg into a separation vessel, separating, by the separationvessel, the first polyolefin from a gas mixture, and treating the gasmixture, wherein the step of treating comprises a flaring a component ofthe gas mixture, capturing a component of the gas mixture in a pressureswing absorber, filtering a component of the gas mixture in a membrane,or a combination thereof.

In a fifth aspect of process D which can be used in combination with anyof the first to the fourth aspects of process D, process D furthercomprises analyzing a sample of the first polyolefin obtain via a sampletake-off conduit fluidly connected to the settling leg.

In a sixth aspect of process D which can be used in combination with anyof the first to the fifth aspects of process D, the first reactor is afluidized bed reactor, wherein receiving the first polyolefin from thefirst reactor into the second reactor comprises flowing the firstpolyolefin and a gas mixture from the fluidized bed reactor into a lockhopper via a product discharge conduit and a first cycling valve.

In a seventh aspect of process D which can be used in combination withthe sixth aspect of process D, process D further comprises flowing thefirst polyolefin and the gas mixture from the lock hopper to aseparation vessel via a second cycling valve, separating the firstpolyolefin from the gas mixture, and treating the gas mixture, whereinthe step of treating comprises a flaring a component of the gas mixture,capturing a component of the gas mixture in a pressure swing absorber,filtering a component of the gas mixture in a membrane, or a combinationthereof.

In an eighth aspect of process D which can be used in combination withany of the first to the seventh aspects of process D, process D furthercomprises analyzing a sample of the first polyolefin obtain via a sampletake-off conduit fluidly connected to the product discharge conduit.

In a ninth aspect of process D which can be used in combination with anyof the first to the eighth aspects of process D, the first reactor is afluidized bed reactor, wherein receiving the first polyolefin from thefirst reactor into the second reactor comprises controlling a flow ofthe first polyolefin in a product discharge conduit fluidly connected tothe fluidized bed reactor with a continuous take-off valve fluidlyconnected to the product discharge conduit.

In a tenth aspect of process D which can be used in combination with theninth aspect of process D, process D further comprises receiving thefirst polyolefin and a gas mixture into a separation vessel coupled tothe continuous take-off valve, separating, by the separation vessel, thefirst polyolefin from the gas mixture, and treating the gas mixture,wherein the step of treating comprises a flaring a component of the gasmixture, capturing a component of the gas mixture in a pressure swingabsorber, filtering a component of the gas mixture in a membrane, or acombination thereof.

In an eleventh aspect of process D which can be used in combination withany of the first to the tenth aspects of process D, process D furthercomprises analyzing a sample of the first polyolefin obtain via a sampletake-off conduit fluidly connected to the product discharge conduit.

In a twelfth aspect of process D which can be used in combination withany of the first to the eleventh aspects of process D, the first reactoris a fluidized bed reactor, wherein the second polyolefin and the thirdpolyolefin from the second reactor are received into the first reactor,and process D further comprises receiving the multimodal polyolefin intoa settling leg placed at least partially within a bottom portion of thefluidized bed reactor, wherein an end of the settling leg opens to thegas distributor and an opposite end extends outside the fluidized bedreactor.

In a thirteenth aspect of process D which can be used in combinationwith the twelfth aspect of process D, the settling leg has an innerdiameter of from about 10.16 cm (4 inches) to about 30.48 cm (12inches).

In a fourteenth aspect of process D which can be used in combinationwith any of the first to the thirteen aspects of process D, process Dfurther comprises receiving the multimodal polyolefin and a gas mixturein a separation vessel coupled to the settling leg, separating, by theseparation vessel, the multimodal polyolefin from the gas mixture, andtreating the gas mixture, wherein the step of treating comprises aflaring a component of the gas mixture, capturing a component of the gasmixture in a pressure swing absorber, filtering a component of the gasmixture in a membrane, or a combination thereof.

In a fifteenth aspect of process D which can be used in combination withany of the first to the fourteenth aspects of process D, process Dfurther comprises analyzing a sample of the multimodal polyolefin obtainvia a sample take-off conduit fluidly connected to the product dischargeconduit.

In a sixteenth aspect of process D which can be used in combination withany of the first to the fifteen aspects of process D, the first reactoris a fluidized bed reactor, wherein the second polyolefin and the thirdpolyolefin from the second reactor are received into the first reactor,and process D further comprises flowing the multimodal polyolefin and agas mixture from the fluidized bed reactor into a lock hopper via aproduct discharge conduit and a first cycling valve.

In a seventeenth aspect of process D which can be used in combinationwith the sixteenth aspect of process D, process D further comprisesflowing the multimodal polyolefin and the gas mixture from the lockhopper to a separation vessel via a second cycling valve, separating themultimodal polyolefin from the gas mixture, and treating the gasmixture, wherein the step of treating comprises a flaring a component ofthe gas mixture, capturing a component of the gas mixture in a pressureswing absorber, filtering a component of the gas mixture in a membrane,or a combination thereof.

In an eighteenth aspect of process D which can be used in combinationwith any of the first to the seventeenth aspects of process D, process Dfurther comprises analyzing a sample of the multimodal polyolefin obtainvia a sample take-off conduit fluidly connected to the product dischargeconduit.

In a nineteenth aspect of process D which can be used in combinationwith any of the first to the eighteenth aspects of process D, the firstreactor is a fluidized bed reactor, wherein the second polyolefin andthe third polyolefin from the second reactor are received into the firstreactor, and process D further comprises controlling a flow of themultimodal polyolefin in a product discharge conduit fluidly connectedto the fluidized bed reactor with a continuous take-off valve fluidlyconnected to the product discharge conduit.

In a twentieth aspect of process D which can be used in combination withthe nineteenth aspect of process D, process D further comprisesreceiving the multimodal polyolefin and a gas mixture into a separationvessel coupled to the continuous take-off valve, separating, by theseparation vessel, the multimodal polyolefin from the gas mixture, andtreating the gas mixture, wherein the step of treating comprises aflaring a component of the gas mixture, capturing a component of the gasmixture in a pressure swing absorber, filtering a component of the gasmixture in a membrane, or a combination thereof.

In a twenty-first aspect of process D which can be used in combinationwith any of the first to the twentieth aspects of process D, process Dfurther comprises analyzing a sample of the multimodal polyolefin obtainvia a sample take-off conduit fluidly connected to the product dischargeconduit.

In a twenty-second aspect of process D which can be used in combinationwith any of the first to the twenty-first aspects of process D, thefirst polyolefin is a lower molecular weight polyethylene, the thirdpolyolefin is a higher molecular weight polyethylene.

In a twenty-third aspect of process D which can be used in combinationwith the twenty-second aspect of process D, the second polyolefin has anaverage molecular weight (M_(w), M_(n), or M_(z)) greater than anaverage molecular weight (M_(w), M_(n), or M_(z)) of the firstpolyolefin and less than an average molecular weight of the thirdpolyolefin.

In a twenty-fourth aspect of process D which can be used in combinationwith any of the first to the twenty-third aspects of process D, fromabout 20 to about 80 wt. % of the multimodal polyolefin comprises thefirst polyolefin and from about 80 to about 20 wt. % of the multimodalpolyolefin comprises the second polyolefin and the third polyolefin.

In a twenty-fifth aspect of process D which can be used in combinationwith any of the first to the twenty-fourth aspects of process D, themultimodal polyolefin has a density in a range of from about 0.930 toabout 0.970 g/ml when tested in accordance with ASTM D1505, a melt indexin a range of from about 0.1 to about 30 g/10 min when tested inaccordance with ASTM D1238 under a force of 2.16 kg and a temperature of190° C., a comonomer content in a range of from 0 to about 6 wt. %, anda M_(w) in a range of from about 250 to about 1,500 kg/mol.

In a twenty-sixth aspect of process D which can be used in combinationwith the twenty-fifth aspect of process D, the multimodal polyolefin hasa high load melt index of from about 1 to about 45 g/10 min when testedin accordance with ASTM D1238 under a force of 21.6 kg and a temperatureof 190° C., a M_(z) in a range of from about 500 to about 5,000 kg/mol,a Mw/Mn in a range of from about 18 to about 52, a long chain branchingindex in a range of from 0 to about 0.96, and a shear inducedcrystallization (SIC) index in a range of from about 0.15 to about 8.

In a twenty-seventh aspect of process D which can be used in combinationwith any of the first to the twenty-sixth aspects of process D, thefirst reactor is a loop slurry reactor, a fluidized bed reactor, anautoclave reactor, a tubular reactor, a horizontal gas phase reactor, acontinuous stirred-tank reactor, or a solution reactor.

A first aspect of apparatus A which is an apparatus for producing amultimodal polyolefin, comprising a first reactor configured to producea first polyolefin, a second reactor configured to produce a secondpolyolefin and a third polyolefin, where the second reactor comprises ariser configured to produce the second polyolefin, an upper conduithaving an end fluidly connected to a top portion of the riser, aseparator fluidly connected to an opposite end of the upper conduit, adowncomer configured to produce the third polyolefin, wherein a topportion of the downcomer is fluidly connected to the separator,optionally via a liquid barrier in the top portion of the downcomer, anda lower conduit having an end fluidly connected to a bottom portion ofthe downcomer and an opposite end fluidly connected to a bottom portionof the riser, wherein the second reactor is configured to receive thefirst polyolefin from the first reactor, or, the first reactor isconfigured to receive the second polyolefin and the third polyolefinfrom the second reactor.

In a second aspect of apparatus A which can be used in combination withthe first aspect of apparatus A, the riser has a width-to-height ratioof less than about 0.1.

In a third aspect of apparatus A which can be used in combination withany of the first to the second aspects of apparatus A, the downcomer hasa width-to-height ratio of less than about 0.1.

In a fourth aspect of apparatus A which can be used in combination withany of the first to the third aspects of apparatus A, the upper conduithas a length-to-diameter ratio of about 5 to about 20.

In a fifth aspect of apparatus A which can be used in combination withany of the first to the fourth aspects of apparatus A, the lower conduithas a length-to-diameter ratio of about 5 to about 20.

In a sixth aspect of apparatus A which can be used in combination withany of the first to the fifth aspects of apparatus A, apparatus Afurther comprises a heat apparatus configured to add or remove heat fromthe riser.

In a seventh aspect of apparatus A which can be used in combination withany of the first to the sixth aspects of apparatus A, apparatus Afurther comprises a heat apparatus configured to add or remove heat fromthe downcomer.

In an eighth aspect of apparatus A which can be used in combination withany of the first to the fourth aspects of apparatus A, the secondreactor further comprises a transition conduit fluidly connected to theend of the lower conduit.

In a ninth aspect of apparatus A which can be used in combination withthe eighth aspect of apparatus A, an angle of the transition conduitwith respect to horizontal is less than about 90°.

In a tenth aspect of apparatus A which can be used in combination withany of the first to the ninth aspects of apparatus A, a length of thetransition conduit is from about 6 feet to about 15 feet.

In an eleventh aspect of apparatus A which can be used in combinationwith any of the first to the tenth aspects of apparatus A, the secondreactor further comprises a first elbow connector connected to thebottom portion of the riser and to the opposite end of the lowerconduit, and a second elbow connector connected to the top portion ofthe riser and to the end of the upper conduit, and a tee connectorhaving a first end connected to the bottom portion of the downcomer, asecond end connected to the lower conduit, and a third end connected toan end of the transition conduit, wherein a first angle between thefirst end and the second end is equal to or less than about 90° and asecond angle between the second end and the third end is equal to orgreater than 90°.

In a twelfth aspect of apparatus A which can be used in combination withany of the first to the eleventh aspects of apparatus A, the secondreactor further comprises a first elbow connector connected to thebottom portion of the riser and to the opposite end of the lowerconduit, a second elbow connector connected to the top portion of theriser and to the end of the upper conduit, and a third elbow connectorconnected to the bottom portion of the downcomer and to the end of thelower conduit.

In a thirteenth aspect of apparatus A which can be used in combinationwith the twelfth aspect of apparatus A, at least one of the first, thesecond, or the third elbow connector has an inner diameter (d) and aradius (R_(c)) of an inner curvature and is configured to maintain aDean number (D_(n)) of a reaction mixture flowing therein to be a valuein a range of from about 1,000,000 to about 5,000,000, whereD_(n)=ρVd/μ*(d/2R_(c))^(1/2) and where p is a density of the reactionmixture, V is a circulation velocity of the reaction mixture, and is adynamic viscosity of the reaction mixture.

In a fourteenth aspect of apparatus A which can be used in combinationwith any of the first to the thirteenth aspects of apparatus A,apparatus A further comprises an elbow connector connected i) to thebottom portion of the riser and to the opposite end of the lowerconduit, ii) to the top portion of the riser and to the end of the upperconduit, or iii) to the bottom portion of the downcomer and to the endof the lower conduit, wherein the elbow connector comprises a first tapon an outside radius of the elbow connector, a second tap on an insideradius of the elbow connector, a first sensing leg coupling the firsttap to a differential pressure meter, and a second sensing leg couplingthe second tap to the differential pressure meter.

In a fifteenth aspect of apparatus A which can be used in combinationwith any of the first to the fourteenth aspects of apparatus A, thesecond reactor has an internal surface which is polished to a root meansquare of less than about 150 microinches.

In a sixteenth aspect of apparatus A which can be used in combinationwith any of the first to the fifteenth aspects of apparatus A, apparatusA further comprises a rust inhibitor coating on an internal surface ofthe first reactor or an internal surface of the second reactor.

In a seventeenth aspect of apparatus A which can be used in combinationwith any of the first to the sixteenth aspects of apparatus A, at leasta portion of the first reactor or at least a portion of the secondreactor is made of carbon steel, stainless steel, or a combinationthereof.

In an eighteenth aspect of apparatus A which can be used in combinationwith any of the first to the seventeenth aspects of apparatus A, atleast a portion of the first reactor or at least a portion of the secondreactor is made of carbon steel, wherein the carbon steel is a lowtemperature carbon steel.

In a nineteenth aspect of apparatus A which can be used in combinationwith any of the first to the eighteenth aspects of apparatus A,apparatus A further comprises one or more thermowells located on thesecond reactor.

In a twentieth aspect of apparatus A which can be used in combinationwith any of the first to the nineteenth aspects of apparatus A, thesecond reactor further comprises an eductor or a standpipe coupled tothe lower conduit or to a transition conduit that is fluidly connectedto the end of the lower conduit.

In a twenty-first aspect of apparatus A which can be used in combinationwith any of the first to the twentieth aspects of apparatus A, thesecond reactor further comprises a gas density meter configured tomeasure a density of a reaction mixture in the riser.

In a twenty-second aspect of apparatus A which can be used incombination with any of the first to the twenty-first aspects ofapparatus A, the first polyolefin is a lower molecular weightpolyethylene, the third polyolefin is a higher molecular weightpolyethylene.

In a twenty-third aspect of apparatus A which can be used in combinationwith the twenty-second aspect of apparatus A, the second polyolefin hasan average molecular weight greater (M_(w), M_(n), or M_(z)) than anaverage molecular weight (M_(w), M_(n), or M_(z)) of the firstpolyolefin and less than an average molecular weight of the thirdpolyolefin.

In a twenty-fourth aspect of apparatus A which can be used incombination with any of the first to the twenty-third aspects ofapparatus A, from about 20 to about 80 wt. % of the multimodalpolyolefin comprises the first polyolefin and from about 8 to about 20wt. % of the multimodal polyolefin comprises the second polyolefin andthe third polyolefin.

In a twenty-fifth aspect of apparatus A which can be used in combinationwith any of the first to the twenty-fourth aspects of apparatus A, themultimodal polyolefin has a density in a range of from about 0.930 toabout 0.970 g/ml when tested in accordance with ASTM D1505, a melt indexin a range of from about 0.1 to about 30 g/10 min when tested inaccordance with ASTM D1238 under a force of 2.16 kg and a temperature of190° C., a comonomer content in a range of from 0 to about 6 wt. %, anda M_(w) in a range of from about 250 to about 1,500 kg/mol.

In a twenty-sixth aspect of apparatus A which can be used in combinationwith the twenty-fifth aspect of apparatus A, the multimodal polyolefinhas a high load melt index of from about 1 to about 45 g/10 min whentested in accordance with ASTM D1238 under a force of 21.6 kg and atemperature of 190° C., a M_(z) in a range of from about 500 to about5,000 kg/mol, a Mw/Mn in a range of from about 18 to about 52, a longchain branching index in a range of from 0 to about 0.96, and a shearinduced crystallization (SIC) index in a range of from about 0.15 toabout 8.

In a twenty-seventh aspect of apparatus A which can be used incombination with any of the first to the twenty-sixth aspects ofapparatus A, wherein the first reactor is a loop slurry reactor, afluidized bed reactor, an autoclave reactor, a tubular reactor, ahorizontal gas phase reactor, a continuous stirred-tank reactor, or asolution reactor.

A first aspect of apparatus B which is an apparatus for producing amultimodal polyolefin, comprising a first reactor configured to producea first polyolefin, a second reactor configured to produce a secondpolyolefin and a third polyolefin, where the second reactor comprises ariser configured to produce the second polyolefin, an upper conduithaving an end fluidly connected to a top portion of the riser, aseparator fluidly connected to an opposite end of the upper conduit, adowncomer configured to produce the third polyolefin, wherein a topportion of the downcomer is fluidly connected to the separator,optionally via a liquid barrier in the top portion of the downcomer, anda lower conduit having an end fluidly connected to a bottom portion ofthe downcomer and an opposite end fluidly connected to a bottom portionof the riser, wherein the second reactor is configured to receive thefirst polyolefin from the first reactor, or, the first reactor isconfigured to receive the second polyolefin and the third polyolefinfrom the second reactor.

In a second aspect of apparatus B which can be used in combination withthe first aspect of apparatus B, apparatus B further comprises a firstproduct discharge conduit fluidly connected to the first reactor, and asecond product discharge conduit fluidly connected to the bottom portionof the downcomer.

In a third aspect of apparatus B which can be used in combination withany of the first to the second aspects of apparatus B, the first productdischarge conduit or the second product discharge conduit is fluidlyconnected to a take-off valve, wherein the take-off valve is configuredas a continuous take-off valve or a discontinuous take-off valve.

In a fourth aspect of apparatus B which can be used in combination withany of the first to the third aspects of apparatus B, the second productdischarge conduit is connected to the downcomer such that an angle ofthe second product discharge conduit with respect to horizontal is 0° to45°.

In a fifth aspect of apparatus B which can be used in combination withany of the first to the fourth aspects of apparatus B, apparatus Bfurther comprises a heater coupled to the second product dischargeconduit and configured to receive a product mixture and to add heat tothe product mixture.

In a sixth aspect of apparatus B which can be used in combination withthe fifth aspect of apparatus B, apparatus B further comprises acatalyst or cocatalyst poison or deactivator added to the productmixture in or upstream of the heater.

In a seventh aspect of apparatus B which can be used in combination withany of the first to the sixth aspects of apparatus B, the heater isfurther configured to discharge the multimodal polyolefin in the productmixture at a temperature i) of about 54.4° C. (130° F.) to about 104.4°C. (220° F.), or ii) below a melting point of the multimodal polyolefin.

In an eighth aspect of apparatus B which can be used in combination withany of the first to the seventh aspects of apparatus B, apparatus Bfurther comprises a separation vessel fluidly connected to an oppositeend of the heater, wherein the separation vessel is configured toseparate the product mixture into a plurality of streams, each of theplurality of streams comprising a vapor, a polymer product, or both thevapor and the polymer product.

In a ninth aspect of apparatus B which can be used in combination withthe eighth aspect of apparatus B, apparatus B further comprises amonomer recovery system configured to recover one or more of an olefinmonomer, an olefin comonomer, and a diluent from at least one of theplurality of streams comprising the vapor and configured to recycle oneor more of the olefin monomer, the olefin comonomer, and the diluent tothe first reactor, the second reactor, or both the first reactor and thesecond reactor.

In a tenth aspect of apparatus B which can be used in combination withany of the first to the ninth aspects of apparatus B, apparatus Bfurther comprises a degassing vessel configured to receive the polymerproduct from the separation vessel and to remove at least a portion of ahydrocarbon entrained within the polymer product.

In an eleventh aspect of apparatus B which can be used in combinationwith any of the first to the tenth aspects of apparatus B, the separatorcomprises a cyclone separator.

In a twelfth aspect of apparatus B which can be used in combination withthe eleventh aspect of apparatus B, the riser is configured to produce ariser product mixture comprising solid particles and a gas mixture,wherein the cyclone separator is configured to receive the riser productmixture via the upper conduit, wherein the cyclone separator is a highefficiency cyclone separator configured to separate 99 wt. % or more ofthe solid particles which have a size of from about 2 μm to about 10 μmfrom the gas mixture.

In a thirteenth aspect of apparatus B which can be used in combinationwith any of the first to the twelfth aspects of apparatus B, the cycloneseparator is configured to have a cone angle with respect to horizontalof about 45° to about 80°.

In a fourteenth aspect of apparatus B which can be used in combinationwith any of the first to the thirteenth aspects of apparatus B, thecyclone separator is configured to have an entrance angle of 0° to about15° with respect to a tangent of the cyclone separator.

In a fifteenth aspect of apparatus B which can be used in combinationwith any of the first to the fourteenth aspects of apparatus B, thecyclone separator is configured to have a tangential entrance velocityof from about 15.24 m/s to about 30.48 m/s.

In a sixteenth aspect of apparatus B which can be used in combinationwith any of the first to the fifteenth aspects of apparatus B, an anglewith respect to horizontal of the opposite end of the upper conduitwhich fluidly connects to the cyclone separator is about 0° to about15°.

In a seventeenth aspect of apparatus B which can be used in combinationwith any of the first to the sixteenth aspects of apparatus B, avertical distance between the opposite end of the upper conduit and atop of the cyclone separator is from about 0 m (0 ft) to about 6.10 m(20 ft).

In an eighteenth aspect of apparatus B which can be used in combinationwith any of the first to the seventeenth aspects of apparatus B,apparatus B further comprises a reactor deactivation system in thesecond reactor, wherein the reactor deactivation system is configured tomoderate or kill polymerization reactions in the riser, the downcomer,or both the riser and the downcomer.

In a nineteenth aspect of apparatus B which can be used in combinationwith any of the first to the eighteenth aspects of apparatus B, theseparator comprises a flash tank or a flash chamber.

In a twentieth aspect of apparatus B which can be used in combinationwith any of the first to the nineteenth aspects of apparatus B, thefirst polyolefin is a lower molecular weight polyethylene, the thirdpolyolefin is a higher molecular weight polyethylene.

In a twenty-first aspect of apparatus B which can be used in combinationwith the twentieth aspect of apparatus B, the second polyolefin has anaverage molecular weight (M_(w), M_(n), or M_(z)) greater than anaverage molecular weight (M_(w), M_(n), or M_(z)) of the firstpolyolefin and less than an average molecular weight of the thirdpolyolefin.

In a twenty-second aspect of apparatus B which can be used incombination with any of the first to the twenty-first aspects ofapparatus B, the first reactor is a loop slurry reactor, a fluidized bedreactor, an autoclave reactor, a tubular reactor, a horizontal gas phasereactor, a continuous stirred-tank reactor, or a solution reactor.

In a twenty-third aspect of apparatus B which can be used in combinationwith any of the first to the twenty-second aspects of apparatus B, fromabout 20 to about 80 wt. % of the multimodal polyolefin comprises thefirst polyolefin and from about 80 to about 20 wt. % of the multimodalpolyolefin comprises the second polyolefin and the third polyolefin.

In a twenty-fourth aspect of apparatus B which can be used incombination with any of the first to the twenty-third aspects ofapparatus B, the multimodal polyolefin has a density in a range of fromabout 0.930 to about 0.970 g/ml, a melt index in a range of from about0.1 to about 30 g/10 min when tested in accordance with ASTM D1238 undera force of 2.16 kg and a temperature of 190° C., a comonomer content ina range of from 0 to about 6 wt. %, and a M_(w) in a range of from about250 to about 1,500 kg/mol.

In a twenty-fifth aspect of apparatus B which can be used in combinationwith the twenty-fourth aspect of apparatus B, the multimodal polyolefinhas a high load melt index of from about 1 to about 45 g/10 min whentested in accordance with ASTM D1238 under a force of 21.6 kg and atemperature of 190° C., a M_(z) in a range of from about 500 to about5,000 kg/mol, a Mw/Mn in a range of about 18 to about 52, a long chainbranching index in a range of from about 0 to about 0.96, and a shearinduced crystallization (SIC) index in a range of from about 0.15 toabout 8.

A first aspect of apparatus C which is an apparatus for producing amultimodal polyolefin, comprising a first reactor configured to producea first polyolefin, a second reactor configured to produce a secondpolyolefin and a third polyolefin, where the second reactor comprises ariser configured to produce the second polyolefin, an upper conduithaving an end fluidly connected to a top portion of the riser, aseparator fluidly connected to an opposite end of the upper conduit andconfigured to separate a polyolefin product from a first reactionmixture received from the upper conduit, a downcomer configured toproduce the third polyolefin, wherein a top portion of the downcomer isfluidly connected to the separator, optionally via a liquid barrier inthe top portion of the downcomer, and a lower conduit having an endfluidly connected to a bottom portion of the downcomer and an oppositeend fluidly connected to a bottom portion of the riser, wherein thelower conduit is configured to pass a second reaction mixture from thedowncomer to the riser, wherein the second reactor is configured toreceive the first polyolefin from the first reactor, or, the firstreactor is configured to receive the second polyolefin and the thirdpolyolefin from the second reactor.

In a second aspect of apparatus C which can be used in combination withthe first aspect of apparatus C, a gas composition of the secondreaction mixture is different than a gas composition of the thirdreaction mixture.

In a third aspect of apparatus C which can be used in combination withany of the first to the second aspects of apparatus C, the gascomposition of the second reaction mixture comprises at least twoselected from monomer, diluent, and a catalyst.

In a fourth aspect of apparatus C which can be used in combination withthe third aspect of apparatus C, the gas composition of the thirdreaction mixture comprises at least two selected from hydrogen, monomer,comonomer, diluent, and a catalyst.

In a fifth aspect of apparatus C which can be used in combination withany of the first to the fourth aspects of apparatus C, the liquidbarrier comprises an inert liquid, wherein a concentration of the inertliquid in the liquid barrier is greater than a concentration of theinert liquid in the downcomer and in the riser.

In a sixth aspect of apparatus C which can be used in combination withany of the first to the fifth aspects of apparatus C, the second reactorfurther comprises one or more comonomer feed lines configured to injectcomonomer into the downcomer, wherein the third polyolefin is acopolymer.

In a seventh aspect of apparatus C which can be used in combination withany of the first to the sixth aspects of apparatus C, apparatus Cfurther comprises one or more anti-static agent feed lines configured toinject an anti-static agent into the second reactor.

In an eighth aspect of apparatus C which can be used in combination withthe seventh aspect of apparatus C, the one or more anti-static agentlines are configured to inject a mixture comprising the anti-staticagent and a carrier fluid, wherein a concentration of the anti-staticagent in each of the one or more anti-static agent feed lines is about 1ppm to about 50 ppm based on weight of the carrier fluid in each of theone or more anti-static agent feed lines.

In a ninth aspect of apparatus C which can be used in combination withany of the first to the eighth aspects of apparatus C, where aconcentration of the anti-static agent in the second reactor is about 1ppm to about 50 ppm based on weight of the carrier fluid in the secondreactor.

In a tenth aspect of apparatus C which can be used in combination withany of the first to the ninth aspects of apparatus C, the upper conduitis configured to pass the first reaction mixture from the riser to theseparator at a velocity that is i) greater than a saltation velocity ofthe first reaction mixture and up to about 30.48 m/s (100 ft/sec), orii) greater than 110% of the saltation velocity of the first reactionmixture.

In an eleventh aspect of apparatus C which can be used in combinationwith any of the first to the tenth aspects of apparatus C, the lowerconduit is further configured to pass the second reaction mixture fromthe downcomer to the riser at a velocity that is i) greater than asaltation velocity of the second reaction mixture and up to about 30.48m/s (100 ft/sec), or ii) greater than 110% of the saltation velocity ofthe second reaction mixture.

In a twelfth aspect of apparatus C which can be used in combination withany of the first to the eleventh aspects of apparatus C, apparatus Cfurther comprises a sample analyzer configured to: i) analyze a sampleof the first reaction mixture or the second reaction mixture at one ormore locations in the second reactor, ii) determine a concentration ofgas, liquid, or solid in the first reaction mixture or the secondreaction mixture, and iii) determine a concentration of monomer,comonomer, diluent, hydrogen, inert component, or polymer in the firstreaction mixture or the second reaction mixture.

In a thirteenth aspect of apparatus C which can be used in combinationwith any of the first to the twelfth aspects of apparatus C, theseparator comprises a level controller coupled to the separator andconfigured to control a level of the polyolefin product in the separatorsuch that the polyolefin product has a residence time of about 1 minuteto about 30 minutes in the separator.

In a fourteenth aspect of apparatus C which can be used in combinationwith any of the first to the thirteenth aspects of apparatus C, fromabout 20 to about 80 wt. % of the multimodal polyolefin comprises thefirst polyolefin and from about 80 to about 20 wt. % of the multimodalpolyolefin comprises the second polyolefin and the third polyolefin.

In a fifteenth aspect of apparatus C which can be used in combinationwith any of the first to the fourteenth aspects of apparatus C, themultimodal polyolefin has a density in a range of from about 0.930 toabout 0.970 g/ml when tested in accordance with ASTM D1505, a melt indexin a range of from about 0.1 to about 30 g/10 min when tested inaccordance with ASTM D1238 under a force of 2.16 kg and a temperature of190° C., a comonomer content in a range of from 0 to about 6 wt. %, anda M_(w) in a range of from about 250 to about 1,500 kg/mol.

In a sixteenth aspect of apparatus C which can be used in combinationwith the fifteenth aspect of apparatus C, the multimodal polyolefin hasa high load melt index of from about 1 to about 45 g/10 min when testedin accordance with ASTM D1238 under a force of 21.6 kg and a temperatureof 190° C., a M_(z) in a range of from about 500 to about 5,000 kg/mol,a Mw/Mn in a range of from about 18 to about 52, a long chain branchingindex in a range of from about 0 to about 0.96, and a shear inducedcrystallization (SIC) index in a range of from about 0.15 to about 8.

In a seventeenth aspect of apparatus C which can be used in combinationwith any of the first to the sixteenth aspects of apparatus C, the firstreactor is a loop slurry reactor, a fluidized bed reactor, an autoclavereactor, a tubular reactor, a horizontal gas phase reactor, a continuousstirred-tank reactor, or a solution reactor.

A first aspect of apparatus D which is an apparatus for producing amultimodal polyolefin, comprising a first reactor configured to producea first polyolefin, a second reactor configured to produce a secondpolyolefin and a third polyolefin, where the second reactor comprises ariser configured to produce the second polyolefin, an upper conduithaving an end fluidly connected to a top portion of the riser, aseparator fluidly connected to an opposite end of the upper conduit, adowncomer configured to produce the third polyolefin, wherein a topportion of the downcomer is fluidly connected to the separator,optionally via a liquid barrier in the top portion of the downcomer, anda lower conduit having an end fluidly connected to a bottom portion ofthe downcomer and an opposite end fluidly connected to a bottom portionof the riser, wherein the second reactor is configured to receive thefirst polyolefin from the first reactor, or, the first reactor isconfigured to receive the second polyolefin and the third polyolefinfrom the second reactor.

In a second aspect of apparatus D which can be used in combination withthe first aspect of apparatus D, the second reactor is configured toreceive the first polyolefin from the first reactor, wherein the firstreactor comprises a fluidized bed reactor, a gas distributor locatedinside the fluidized bed reactor in a bottom portion thereof, and asettling leg placed at least partially within the bottom portion of thefluidized bed reactor, wherein an end of the settling leg opens to thegas distributor and an opposite end extends outside the fluidized bedreactor.

In a third aspect of apparatus D which can be used in combination withany of the first to the second aspects of apparatus D, wherein thesettling leg has an inner diameter of from about 10.16 cm (4 inches) toabout 30.48 cm (12 inches).

In a fourth aspect of apparatus D which can be used in combination withany of the first to the third aspects of apparatus D, apparatus Dfurther comprises a separation vessel coupled to the settling leg andconfigured to separate the first polyolefin from a gas mixture, and atreater configured to treat the gas mixture, wherein the treatercomprises a flare stack or ground flare, a pressure swing absorber, amembrane, or a combination thereof.

In a fifth aspect of apparatus D which can be used in combination withany of the first to the fourth aspects of apparatus D, apparatus Dfurther comprises a product discharge conduit fluidly connected to thesettling leg, and a sampling system fluidly connected to the productdischarge conduit and configured to analyze a sample of the firstpolyolefin.

In a sixth aspect of apparatus D which can be used in combination withany of the first to the fifth aspects of apparatus D, the second reactoris configured to receive the first polyolefin from the first reactor,wherein the first reactor comprises a fluidized bed reactor, a productdischarge conduit fluidly connected to the fluidized bed reactor, a lockhopper coupled to the product discharge conduit, a first cycling valvecoupled to the product discharge conduit and to the lock hopper, and asecond cycling valve coupled to an outlet of the lock hopper.

In a seventh aspect of apparatus D which can be used in combination withthe sixth aspect of apparatus D, apparatus D further comprises aseparation vessel coupled to the second cycling valve and configured toseparate the first polyolefin from a gas mixture, and a treaterconfigured to treat the gas mixture, wherein the treater comprises aflare stack or ground flare, a pressure swing absorber, a membrane, or acombination thereof.

In an eighth aspect of apparatus D which can be used in combination withany of the first to the seventh aspects of apparatus D, apparatus Dfurther comprises a sampling system fluidly connected to the productdischarge conduit and configured to analyze a sample of the firstpolyolefin.

In a ninth aspect of apparatus D which can be used in combination withany of the first to the eighth aspects of apparatus D, the secondreactor is configured to receive the first polyolefin from the firstreactor, wherein the first reactor comprises a fluidized bed reactor, aproduct discharge conduit fluidly connected to the fluidized bedreactor, and a continuous take-off valve fluidly connected to theproduct discharge conduit.

In a tenth aspect of apparatus D which can be used in combination withthe ninth aspect of apparatus D, apparatus D further comprises aseparation vessel coupled to the continuous take-off valve andconfigured to separate the first polyolefin from a gas mixture, and atreater configured to treat the gas mixture, wherein the treatercomprises a flare stack or ground flare, a pressure swing absorber, amembrane, or a combination thereof.

In an eleventh aspect of apparatus D which can be used in combinationwith any of the first to the tenth aspects of apparatus D, apparatus Dfurther comprises a sampling system fluidly connected to the productdischarge conduit and configured to analyze a sample of the firstpolyolefin.

In a twelfth aspect of apparatus D which can be used in combination withany of the first to the eleventh aspects of apparatus D, the firstreactor is configured to receive the second polyolefin and the thirdpolyolefin from the second reactor, wherein the first reactor comprisesa fluidized bed reactor, a gas distributor located inside the fluidizedbed reactor in a bottom portion thereof, and a settling leg placed atleast partially within the bottom portion of the fluidized bed reactor,wherein an end of the settling leg opens to the gas distributor and anopposite end extends outside the fluidized bed reactor.

In a thirteenth aspect of apparatus D which can be used in combinationwith the twelfth aspect of apparatus D, the settling leg has an innerdiameter of from about 10.16 cm (4 inches) to about 30.48 cm (12inches).

In a fourteenth aspect of apparatus D which can be used in combinationwith any of the first to the thirteenth aspects of apparatus D,apparatus D further comprises a separation vessel coupled to thesettling leg and configured to separate the multimodal polyolefin from agas mixture, and a treater configured to treat the gas mixture, whereinthe treater comprises a flare stack or ground flare, a pressure swingabsorber, a membrane, or a combination thereof.

In a fifteen aspect of apparatus D which can be used in combination withany of the first to the fourteenth aspects of apparatus D, apparatus Dfurther comprises a product discharge conduit fluidly connected to thesettling leg, and a sampling system fluidly connected to the productdischarge conduit and configured to analyze a sample of the multimodalpolyolefin.

In a sixteenth aspect of apparatus D which can be used in combinationwith any of the first to the fifteenth aspects of apparatus D, the firstreactor is configured to receive the second polyolefin and the thirdpolyolefin from the second reactor, wherein the first reactor comprisesa fluidized bed reactor, a product discharge conduit fluidly connectedto the fluidized bed reactor, a lock hopper coupled to the productdischarge conduit, a first cycling valve coupled to the productdischarge conduit and to an inlet of the lock hopper, and a secondcycling valve coupled to an outlet of the lock hopper.

In a seventeenth aspect of apparatus D which can be used in combinationwith the sixteenth aspect of apparatus D, apparatus D further comprisesa separation vessel coupled to the second cycling valve and configuredto separate the multimodal polyolefin from a gas mixture, and a treaterconfigured to treat the gas mixture, wherein the treater comprises aflare stack or ground flare, a pressure swing absorber, a membrane, or acombination thereof.

In an eighteenth aspect of apparatus D which can be used in combinationwith any of the first to the seventeenth aspects of apparatus D,apparatus D further comprises a sampling system fluidly connected to theproduct discharge conduit and configured to analyze a sample of themultimodal polyolefin.

In a nineteenth aspect of apparatus D which can be used in combinationwith any of the first to the eighteenth aspects of apparatus D, thefirst reactor is configured to receive the second polyolefin and thethird polyolefin from the second reactor, wherein the first reactorcomprises a fluidized bed reactor, a product discharge conduit fluidlyconnected to the fluidized bed reactor, and a continuous take-off valvefluidly connected to the product discharge conduit.

In a twentieth aspect of apparatus D which can be used in combinationwith the nineteenth aspect of apparatus D, apparatus D further comprisesa separation vessel coupled to the continuous take-off valve andconfigured to separate the multimodal polyolefin from a gas mixture, anda treater configured to treat the gas mixture, wherein the treatercomprises a flare stack or ground flare, a pressure swing absorber, amembrane, or a combination thereof.

In a twenty-first aspect of apparatus D which can be used in combinationwith any of the first to the twentieth aspects of apparatus D, apparatusD further comprises a sampling system fluidly connected to the productdischarge conduit and configured to analyze a sample of the multimodalpolyolefin.

In a twenty-second aspect of apparatus D which can be used incombination with any of the first to the twenty-first aspects ofapparatus D, the first polyolefin is a lower molecular weightpolyethylene, the third polyolefin is a higher molecular weightpolyethylene.

In a twenty-third aspect of apparatus D which can be used in combinationwith the twenty-second aspect of apparatus D, the second polyolefin hasan average molecular weight (M_(w), M_(n), or M_(z)) greater than anaverage molecular weight (M_(w), M_(n), or M_(z)) of the firstpolyolefin and less than an average molecular weight of the thirdpolyolefin.

In a twenty-fourth aspect of apparatus D which can be used incombination with any of the first to the twenty-third aspects ofapparatus D, wherein from about 20 to about 80 wt. % of the multimodalpolyolefin comprises the first polyolefin and from about 80 to about 20wt. % of the multimodal polyolefin comprises the second polyolefin andthe third polyolefin.

In a twenty-fifth aspect of apparatus D which can be used in combinationwith any of the first to the twenty-fourth aspects of apparatus D, themultimodal polyolefin has a density in a range of from about 0.930 toabout 0.970 g/ml when tested in accordance with ASTM D1505, a melt indexin a range of from about 0.1 to about 30 g/10 min when tested inaccordance with ASTM D1238 under a force of 2.16 kg and a temperature of190° C., a comonomer content in a range of from 0 to about 6 wt. %, anda M_(w) in a range of from about 250 to about 1,500 kg/mol.

In a twenty-sixth aspect of apparatus D which can be used in combinationwith the twenty-fifth aspect of apparatus D, the multimodal polyolefinhas a high load melt index of from about 1 to about 45 g/10 min whentested in accordance with ASTM D1238 under a force of 21.6 kg and atemperature of 190° C., a M_(z) in a range of from about 500 to about5,000 kg/mol, a Mw/Mn in a range of from about 18 to about 52, a longchain branching index in a range of from 0 to about 0.96, and a shearinduced crystallization (SIC) index in a range of from about 0.15 toabout 8.

In a twenty-seventh aspect of apparatus D which can be used incombination with any of the first to the twenty-sixth aspects ofapparatus D, the first reactor is a loop slurry reactor, a fluidized bedreactor, an autoclave reactor, a tubular reactor, a horizontal gas phasereactor, a continuous stirred-tank reactor, or a solution reactor.

In a first aspect, polyethylene resin A can comprise the firstpolyolefin made in polymerization zone 112 of the first reactor 100, thesecond polyolefin made in the polymerization zone 321 of the riser 320of the MZCR 300, and the third polyolefin made in the polymerizationzone 341 of the downcomer 340 of the MZCR 300.

In a second aspect that can be in combination with the first aspect, thefirst polyolefin in polyethylene resin A can be a low molecular weight(LMW) component of the multimodal polyolefin, the second polyolefin inpolyethylene resin A can be an intermediate molecular weight (IMW)component of the multimodal polyolefin, and the third polyolefin inpolyethylene resin A can be a high molecular weight component (HMW) ofthe multimodal polyolefin.

In a third aspect that can be in combination with the first and secondaspects, the first polyolefin (e.g., the LMW component) in polyethyleneresin A that is produced in the polymerization zone 112 of the firstreactor 100 can be a lower molecular weight polyethylene, the secondpolyolefin (e.g., the IMW component) in polyethylene resin A that isproduced in the polymerization zone 321 of the riser 320, the thirdpolyolefin (e.g., the HMW component) in polyethylene resin A that isproduced in the polymerization zone 341 of the downcomer 340 can be ahigher molecular weight polyethylene, or combinations thereof.

In a fourth aspect that can be in combination with any of the first tothird aspects, an amount of from about 20 to about 80 wt. % ofpolyethylene resin A can comprise the first polyolefin and an amount offrom about 80 to about 20 wt. % of polyethylene resin A can comprise thesecond polyolefin and the third polyolefin.

In a fifth aspect that can be in combination with any of the first tofourth aspects, an amount of from about 20 to about 80 wt. % ofpolyethylene resin A can comprise the LMW components and an amount offrom about 80 to about 20 wt. % of polyethylene resin A can comprise theIMW component and the HMW component.

In a sixth aspect that can be in combination with any of the first tofifth aspects, the LMW component can be present in polyethylene resin Ain an amount of from about 20 wt. % to about 75 wt. %, the IMW componentcan be present in polyethylene resin A in an amount of from about 5 wt.% to about 40 wt. %, and the HMW component can be present inpolyethylene resin A in an amount of from about 10 wt. % to about 60 wt.%.

In a seventh aspect that can be in combination with any of the first tosixth aspects, polyethylene resin A can have a density in a range ofabout 0.930 to about 0.970 g/ml, when tested in accordance with ISO 1183at 23° C.

In an eighth aspect that can be in combination with any of the first toseventh aspects, polyethylene resin A can have a melt index (MI₂) in arange of from about 0.1 to about 30 g/10 min, when tested in accordancewith ISO 1133 at 190° C. under a force of 2.16 kg.

In a ninth aspect that can be in combination with any of the first toeighth aspects, polyethylene resin A can have a high load melt index(HLMI) of from about 1 to about 45 g/10 min, when tested in accordancewith ISO 1133 at 190° C. under a force of 21.6 kg.

In a tenth aspect that can be in combination with any of the first toninth aspects, polyethylene resin A can have a comonomer content in arange of from about 0 to about 6 wt. %.

In an eleventh aspect that can be in combination with any of the firstto tenth aspects, polyethylene resin A can have a weight averagemolecular weight (M_(w)) in a range of from about 250 to about 1,500kg/mol.

In a twelfth aspect that can be in combination with any of the first toeleventh aspects, polyethylene resin A can have a z-average molecularweight (M_(z)) in a range of from about 500 to about 5,000 kg/mol.

In a thirteenth aspect that can be in combination with any of the firstto twelfth aspects, polyethylene resin A can have a polydispersity index(dispersity or PDI or M_(w)/M_(n)) in a range of from about 18 to about52.

In a fourteenth aspect that can be in combination with any of the firstto thirteenth aspects, polyethylene resin A can have a long chainbranching index in a range of from about 0 to about 0.96.

In a fifteenth aspect that can be in combination with any of the firstto fourteenth aspects, polyethylene resin A can have a shear inducedcrystallization (SIC) index in a range of from about 0.15 to about 8.

In a sixteenth aspect that can be in combination with any of the firstto fifteenth aspects, the second polyolefin (e.g., the IMW component) inpolyethylene resin A that is produced in polymerization zone 321 of theriser 320 can have an average molecular weight (M_(w), M_(n), or M_(z))greater than an average molecular weight (M_(w), M_(n), or M_(z)) of thefirst polyolefin (e.g., the LMW component) in polyethylene resin A thatis produced in the polymerization zone 112 of the first reactor 100 andless than an average molecular weight (M_(w), M_(n), or M_(z)) of thethird polyolefin (e.g., the HMW component) in polyethylene resin A thatis produced in the polymerization zone 341 of the downcomer 340.

In a seventeenth aspect that can be in combination with any of the firstto sixteenth aspects, polyethylene resin A can have an environmentalstress cracking resistance (ESCR) of equal to or greater than about 800hours; alternatively, greater than about 900 hours; alternatively,greater than about 1,000 hours, when tested in accordance with ISO16770.

In an eighteenth aspect that can be in combination with any of the firstto seventeenth aspects, polyethylene resin A can have a value for rapidcrack propagation (RCP) that is at least 100%; alternatively, at least110%; alternatively, at least 120%; alternatively, at least 130%;alternatively, at least 140% of the value for RCP of a bimodalpolyethylene.

In a nineteenth aspect that can be in combination with any of the firstto eighteenth aspects, polyethylene resin A can have a value for rapidcrack propagation (RCP) that is at least 100%; alternatively, at least110%; alternatively, at least 120%; alternatively, at least 130%;alternatively, at least 140% of the value for RCP of a bimodalpolyethylene.

In a twentieth aspect that can be in combination with any of the firstto nineteenth aspects, polyethylene resin A can have a resistance toslow crack growth of at least 100%; alternatively, at least 110%;alternatively, at least 120%; alternatively, at least 130%;alternatively, at least 140% of the value for resistance to slow crackgrowth of a bimodal polyethylene, when tested in accordance with ASTMF1473, with the caveat that the resistance to slow crack growth isdefined as the polyethylene notch tensile test (PENT) failure time.

In a twenty-first aspect that can be in combination with any of thefirst to twentieth aspects, polyethylene resin A can have a tensileimpact strength of from about 135 to about 165 kJ/m².

In a twenty-second aspect that can be in combination with any of thefirst to twenty-first aspects, polyethylene resin A can be made by anyembodiment of the process having any combination of the aspectsdescribed herein.

In a twenty-third aspect that can be in combination with any of thefirst to twenty-second aspects, polyethylene resin A can have a gelcount of less than about 950 gels/m²; alternatively, polyethylene resinA can have a gel count of less than about 900 gels/m²; alternatively,less than about 850 gels/m²; alternatively, less than about 800 gels/m²;alternatively, less than about 750 gels/m²; alternatively, a gel countof less than about 700 gels/m²; alternatively, less than about 650gels/m²; alternatively, less than about 600 gels/m².

In a first aspect, polyethylene resin B can comprise the firstpolyolefin made in polymerization zone 112 of the first reactor 100, thesecond polyolefin made in the polymerization zone 321 of the riser 320of the MZCR 300, and the third polyolefin made in the polymerizationzone 341 of the downcomer 340 of the MZCR 300.

In a second aspect that can be in combination with the first aspect, thefirst polyolefin in polyethylene resin B can be a low molecular weight(LMW) component of the multimodal polyolefin, the second polyolefin inpolyethylene resin B can be an intermediate molecular weight (IMW)component of the multimodal polyolefin, and the third polyolefin inpolyethylene resin B can be a high molecular weight component (HMW) ofthe multimodal polyolefin.

In a third aspect that can be in combination with any of the first andthe second aspects, the first polyolefin (e.g., the LMW component) inpolyethylene resin B that is produced in the polymerization zone 112 ofthe first reactor 100 can be a lower molecular weight polyethylene, thesecond polyolefin (e.g., the IMW component) in polyethylene resin B thatis produced in the polymerization zone 321 of the riser 320, the thirdpolyolefin (e.g., the HMW component) in polyethylene resin B that isproduced in the polymerization zone 341 of the downcomer 340 can be ahigher molecular weight polyethylene, or combinations thereof.

In a fourth aspect that can be in combination with any of the first tothe third aspects, the LMW component is present in polyethylene resin Bin an amount of from about 20 wt. % to about 75 wt. %.

In a fifth aspect that can be in combination with any of the first tothe fourth aspects, the IMW component is present in polyethylene resin Bin an amount of from about 5 wt. % to about 40 wt. %.

In a sixth aspect that can be in combination with any of the first tothe fifth aspects, the HMW component is present in polyethylene resin Bin an amount of from about 10 wt. % to about 60 wt. %.

In a seventh aspect that can be in combination with any of the first tothe sixth aspects, the LMW component in polyethylene resin B has aweight average molecular weight of from about 20 kg/mol to about 150kg/mol.

In an eighth aspect that can be in combination with any of the first tothe seventh aspects, the IMW component in polyethylene resin B has aweight average molecular weight of from about 85 kg/mol to about 350kg/mol.

In a ninth aspect that can be in combination with any of the first tothe eighth aspects, the HMW component in polyethylene resin B has weightaverage molecular weight of greater than about 350 kg/mol.

In a tenth aspect that can be in combination with any of the first tothe ninth aspects, the weight average molecular weight of the IMWcomponent in polyethylene resin B is greater than the weight averagemolecular weight of the LMW component.

In an eleventh aspect that can be in combination with any of the firstto the tenth aspects, the LMW component in polyethylene resin B has ashort chain branching content of from about 0 to about 5 short chainbranches per 1,000 carbon atoms.

In a twelfth aspect that can be in combination with any of the first tothe eleventh aspects, the IMW component in polyethylene resin B has ashort chain branching content of from about 0.1 to about 10 short chainbranches per 1,000 carbon atoms.

In a thirteenth aspect that can be in combination with any of the firstto the twelfth aspects, the HMW component in polyethylene resin B has ashort chain branching content of from about 1 to about 15 short chainbranches per 1,000 carbon atoms.

In a fourteenth aspect that can be in combination with any of the firstto the thirteenth aspects, the polyethylene resin B has a magnitude ofslip-stick of from about 300 psi to about 1,000 psi (about 2.07 MPa toabout 6.89 MPa).

In a fifteenth aspect that can be in combination with any of the firstto the fourteenth aspects, the polyethylene resin B is a trimodalpolyethylene resin.

In a sixteenth aspect that can be in combination with any of the firstto the fifteen aspects, polyethylene resin B can have a long chainbranching content of less than about 0.01 long chain branches per 1,000carbon atoms.

In a seventeenth aspect that can be in combination with any of the firstto the sixteenth aspects, polyethylene B comprises a comonomer, thepolyethylene resin B has a comonomer content of from greater than about0 wt. % to about 20 wt. %.

In an eighteenth aspect that can be in combination with any of the firstto the seventeenth aspects, the comonomer in the polyethylene resin Bcomprises 1-butene, 1-hexene, 1-octene, or combinations thereof.

In a nineteenth aspect that can be in combination with any of the firstto the eighteenth aspects, the polyethylene resin B can have a comonomercontent of from greater than about 0 wt. % to about 6 wt. %.

In a twentieth aspect that can be in combination with any of the firstto the nineteenth aspects, the polyethylene resin B can have a comonomercontent of from about 2 wt. % to about 6 wt. %.

In a twenty-first aspect that can be in combination with any of thefirst to the twentieth aspects, the polyethylene resin B can have acomonomer content of from about 1 wt. % to about 5 wt. %.

In a twenty-second aspect that can be in combination with any of thefirst to the twenty-first aspects, the polyethylene resin B can have acomonomer content of from greater than about 6 wt. % to about 20 wt. %;alternatively, from greater than about 6 wt. % to about 15 wt. %;alternatively, from greater than about 6 wt. % to about 10 wt. %.

In a twenty-third aspect that can be in combination with any of thefirst to the twenty-second aspects, the polyethylene resin B can have adensity of from about 0.900 g/cc to about 0.980 g/cc, when tested inaccordance with ASTM D1505.

In a twenty-fourth aspect that can be in combination with any of thefirst to the twenty-third aspects, the polyethylene resin B can have adensity of less than about 0.960 g/cc, when tested in accordance withASTM D1505.

In a twenty-fifth aspect that can be in combination with any of thefirst to the twenty-fourth aspects, the polyethylene resin B can have adensity of from greater than about 0.940 g/cc to about 0.960 g/cc, whentested in accordance with ASTM D1505.

In a twenty-sixth aspect that can be in combination with any of thefirst to the twenty-fifth aspects, the polyethylene resin B can have adensity of from about 0.920 g/cc to about 0.940 g/cc, when tested inaccordance with ASTM D1505.

In a twenty-seventh aspect that can be in combination with any of thefirst to the twenty-sixth aspects, the polyethylene resin B can have amelt index of less than about 1 g/10 min, when tested in accordance withASTM D1238 under a force of 2.16 kg.

In a twenty-eighth aspect that can be in combination with any of thefirst to the twenty-seventh aspects, the polyethylene resin B can have ahigh load melt index of from about 1 g/10 min to less than about 20 g/10min, when tested in accordance with ASTM D1238 under a force of 21.6 kg.

In a twenty-ninth aspect that can be in combination with any of thefirst to the twenty-eighth aspects, the polyethylene resin B can have aweight average molecular weight (M_(w)) of from about 150 kg/mol toabout 1,000 kg/mol.

In a thirtieth aspect that can be in combination with any of the firstto the twenty-ninth aspects, the polyethylene resin B can have a numberaverage molecular weight (M_(w)) of from about 7.5 kg/mol to about 30kg/mol.

In a thirty-first aspect that can be in combination with any of thefirst to the thirtieth aspects, the polyethylene resin B can have az-average molecular weight (M_(z)) of from about 1,000 kg/mol to about5,000 kg/mol; alternatively from about 1,000 kg/mol to about 3,500kg/mol.

In a thirty-second aspect that can be in combination with any of thefirst to the thirty-first aspects, the polyethylene resin B can have a(z+1)-average molecular weight (M_(z+1)) of from about 2,000 kg/mol toabout 9,000 kg/mol.

In a thirty-third aspect that can be in combination with any of thefirst to the thirty-second aspects, the polyethylene resin B can have apolydispersity index (PDI) of from about 5 to about 60.

In a thirty-fourth aspect that can be in combination with any of thefirst to the thirty-third aspects, the polyethylene resin B can have apolydispersity index (PDI) of less than about 18.

In a thirty-fifth aspect that can be in combination with any of thefirst to the thirty-fourth aspects, the LMW component of thepolyethylene resin B is a homopolymer.

In a thirty-sixth aspect that can be in combination with any of thefirst to the thirty-fifth aspects, the LMW component of the polyethyleneresin B has a density of less than about 0.960 g/cc, when tested inaccordance with ASTM D1505.

In a thirty-seventh aspect that can be in combination with any of thefirst to the thirty-sixth aspects, the LMW component of the polyethyleneresin B has a density of from equal to or greater than about 0.960 g/ccto about 0.985 g/cc, when tested in accordance with ASTM D1505.

In a thirty-eighth aspect that can be in combination with any of thefirst to the thirty-seventh aspects, the LMW component of thepolyethylene resin B has a melt index of from about 3 g/10 min to about400 g/10 min, when tested in accordance with ASTM D1238 under a force of2.16 kg; and wherein the LMW component has a high load melt index offrom about 160 g/10 min to about 41,000 g/10 min, when tested inaccordance with ASTM D1238 under a force of 21.6 kg.

In a thirty-ninth aspect that can be in combination with any of thefirst to the thirty-eighth aspects, the LMW component of thepolyethylene resin B has a number average molecular weight (M_(n)) offrom about 5 kg/mol to about 25 kg/mol; alternatively, from about 5kg/mol to about 15 kg/mol.

In a fortieth aspect that can be in combination with any of the first tothe thirty-ninth aspects, the LMW component of the polyethylene resin Bhas a z-average molecular weight (M_(z)) of from about 100 kg/mol toabout 340 kg/mol.

In a forty-first aspect that can be in combination with any of the firstto the fortieth aspects, the LMW component of the polyethylene resin Bhas a polydispersity index (PDI) of from about 1 to about 30;alternatively, from about 1 to about 15.

In a forty-second aspect that can be in combination with any of thefirst to the forty-first aspects, the LMW component of the polyethyleneresin B has a short chain branching content of from about 0 to about 4short chain branches per 1,000 carbon atoms.

In a forty-third aspect that can be in combination with any of the firstto the forty-second aspects, the LMW component of the polyethylene resinB has a short chain branching content of from about 0 to about 3 shortchain branches per 1,000 carbon atoms.

In a forty-fourth aspect that can be in combination with any of thefirst to the forty-third aspects, the LMW component of the polyethyleneresin B has a short chain branching content of from about 0 to about 2short chain branches per 1,000 carbon atoms.

In a forty-fifth aspect that can be in combination with any of the firstto the forty-fourth aspects, the LMW component of the polyethylene resinB has a short chain branching content of from about 0 to about 1 shortchain branches per 1,000 carbon atoms.

In a forty-sixth aspect that can be in combination with any of the firstto the forty-fifth aspects, the IMW component of the polyethylene resinB is a copolymer.

In a forty-seventh aspect that can be in combination with any of thefirst to the forty-sixth aspects, the IMW component of the polyethyleneresin B has a first comonomer content of from greater than about 0 wt. %to about 10 wt. %; alternatively, from greater than about 0 wt. % toabout 4 wt. %.

In a forty-eighth aspect that can be in combination with any of thefirst to the forty-seventh aspects, the IMW component of thepolyethylene resin B has a density of from equal to or greater thanabout 0.915 g/cc to about 0.970 g/cc, when tested in accordance withASTM D1505.

In a forty-ninth aspect that can be in combination with any of the firstto the forty-eighth aspects, the IMW component of the polyethylene resinB has a melt index of from about 0.1 g/10 min to about 30 g/10 min, whentested in accordance with ASTM D1238 under a force of 2.16 kg.

In a fiftieth aspect that can be in combination with any of the first tothe forty-ninth aspects, the IMW component of the polyethylene resin Bhas a high load melt index of from about 5 g/10 min to about 1,500 g/10min, when tested in accordance with ASTM D1238 under a force of 21.6 kg.

In a fifty-first aspect that can be in combination with any of the firstto the fiftieth aspects, the IMW component of the polyethylene resin Bhas a number average molecular weight (M_(n)) of from about 10 kg/mol toabout 185 kg/mol; alternatively, from about 10 kg/mol to about 100kg/mol; alternatively, from about 10 kg/mol to about 35 kg/mol.

In a fifty-second aspect that can be in combination with any of thefirst to the fifty-first aspects, the IMW component of the polyethyleneresin B has a z-average molecular weight (M_(z)) of from about 215kg/mol to about 2,300 kg/mol.

In a fifty-third aspect that can be in combination with any of the firstto the fifty-second aspects, the IMW component of the polyethylene resinB has a polydispersity index (PDI) of from about 2.5 to about 35;alternatively from about 2.5 to about 25.

In a fifty-fourth aspect that can be in combination with any of thefirst to the fifty-third aspects, the IMW component of the polyethyleneresin B has a short chain branching content of from about 0.1 to about 8short chain branches per 1,000 carbon atoms.

In a fifty-fifth aspect that can be in combination with any of the firstto the fifty-fourth aspects, the IMW component of the polyethylene resinB has a short chain branching content of from about 0.2 to about 7 shortchain branches per 1,000 carbon atoms.

In a fifty-sixth aspect that can be in combination with any of the firstto the fifty-fifth aspects, the IMW component of the polyethylene resinB has a short chain branching content of from about 0.3 to about 6 shortchain branches per 1,000 carbon atoms.

In a fifty-seventh aspect that can be in combination with any of thefirst to the fifty-sixth aspects, the IMW component of the polyethyleneresin B has a short chain branching content of from about 0.4 to about 5short chain branches per 1,000 carbon atoms.

In a fifty-eighth aspect that can be in combination with any of thefirst to the fifty-seventh aspects, the HMW component of thepolyethylene resin B is a copolymer.

In a fifty-ninth aspect that can be in combination with any of the firstto the fifty-eighth aspects, the HMW component of the polyethylene resinB has a second comonomer content of greater than about 0 wt. % to about10 wt. %; alternatively from about 1 wt. % to about 10 wt. %.

In a sixtieth aspect that can be in combination with any of the first tothe fifty-ninth aspects, the second comonomer content of thepolyethylene resin B is greater than the first comonomer content.

In a sixty-first aspect that can be in combination with any of the firstto the sixtieth aspects, the HMW component of the polyethylene resin Bhas a density of from equal to or greater than about 0.900 g/cc to about0.960 g/cc; alternatively from equal to or greater than about 0.900 g/ccto about 0.940 g/cc; alternatively, from equal to or greater than about0.900 g/cc to about 0.930 g/cc, when tested in accordance with ASTMD1505.

In a sixty-second aspect that can be in combination with any of thefirst to the sixty-first aspects, the HMW component of the polyethyleneresin B has a melt index of less than about 0.1 g/10 min, when tested inaccordance with ASTM D1238 under a force of 2.16 kg.

In a sixty-third aspect that can be in combination with any of the firstto the sixty-second aspects, the HMW component of the polyethylene resinB has a high load melt index of from about 0.005 g/10 min to about 2g/10 min, when tested in accordance with ASTM D1238 under a force of21.6 kg.

In a sixty-fourth aspect that can be in combination with any of thefirst to the sixty-third aspects, the HMW component of the polyethyleneresin B has weight average molecular weight of from greater than about350 kg/mol to about 1,500 kg/mol.

In a sixty-fifth aspect that can be in combination with any of the firstto the sixty-fourth aspects, the HMW component of the polyethylene resinB has a number average molecular weight (M_(n)) of from about 75 kg/molto about 200 kg/mol.

In a sixty-sixth aspect that can be in combination with any of the firstto the sixty-fifth aspects, the HMW component of the polyethylene resinB has a z-average molecular weight (M_(z)) of from about 1,700 kg/mol toabout 4,600 kg/mol.

In a sixty-seventh aspect that can be in combination with any of thefirst to the sixty-sixth aspects, the HMW component of the polyethyleneresin B has a polydispersity index (PDI) of from about 2 to about 20;alternatively, from about 2 to about 15.

In a sixty-eighth aspect that can be in combination with any of thefirst to the sixty-seventh aspects, the HMW component of thepolyethylene resin B has a short chain branching content of from about 2to about 13 short chain branches per 1,000 carbon atoms.

In a sixty-ninth aspect that can be in combination with any of the firstto the sixty-eighth aspects, the HMW component of the polyethylene resinB has a short chain branching content of from about 3 to about 12 shortchain branches per 1,000 carbon atoms.

In a seventieth aspect that can be in combination with any of the firstto the sixty-ninth aspects, the HMW component of the polyethylene resinB has a short chain branching content of from about 4 to about 11 shortchain branches per 1,000 carbon atoms.

In a seventy-first aspect that can be in combination with any of thefirst to the seventieth aspects, the HMW component of the polyethyleneresin B has a short chain branching content of from about 5 to about 10short chain branches per 1,000 carbon atoms.

In a seventy-second aspect that can be in combination with any of thefirst to the seventy-first aspects, the polyethylene resin B can have aYoung's modulus (E) of equal to or greater than about 900 MPa;alternatively, from about 900 MPa to about 1350 MPa, when tested inaccordance with ASTM D638.

In a seventy-third aspect that can be in combination with any of thefirst to the seventy-second aspects, the polyethylene resin B can have atensile yield stress of equal to or greater than about 20 MPa;alternatively, from about 20 MPa to about 30 MPa, when tested inaccordance with ASTM D638.

In a seventy-fourth aspect that can be in combination with any of thefirst to the seventy-third aspects, the polyethylene resin B can have atensile yield strain of from about 5% to about 25%, when tested inaccordance with ASTM D638.

In a seventy-fifth aspect that can be in combination with any of thefirst to the seventy-fourth aspects, the polyethylene resin B can have atensile natural draw ratio at room temperature of from about 300% toabout 600%, when tested in accordance with ASTM D638.

In a seventy-sixth aspect that can be in combination with any of thefirst to the seventy-fifth aspects, the polyethylene resin B can have atensile natural draw ratio at 80° C. of less than 500%, when tested inaccordance with ASTM D638.

In a seventy-seventh aspect that can be in combination with any of thefirst to the seventy-sixth aspects, the polyethylene resin B can have atensile natural draw ratio at 80° C. of less than about 400%, whentested in accordance with ASTM D638.

In a seventy-eighth aspect that can be in combination with any of thefirst to the seventy-seventh aspects, the polyethylene resin B can havea tensile natural draw ratio at 80° C. of from about 250% to about 400%,when tested in accordance with ASTM D638.

In a seventy-ninth aspect that can be in combination with any of thefirst to the seventy-eighth aspects, the polyethylene resin B can have atensile natural draw ratio at 80° C. of less than about 300%, whentested in accordance with ASTM D638.

In an eightieth aspect that can be in combination with any of the firstto the seventy-ninth aspects, the polyethylene resin B can have a strainhardening modulus of from about 50 MPa to about 90 MPa, when tested inaccordance with ISO 18488-2015(E).

In an eighty-first aspect that can be in combination with any of thefirst to the eightieth aspects, the polyethylene resin B can have anenvironmental stress cracking resistance (ESCR) of equal to or greaterthan about 1,000 hours, when tested in accordance with ASTM D1693(condition A).

In an eighty-second aspect that can be in combination with any of thefirst to the eighty-first aspects, the polyethylene resin B can have aresistance to slow crack growth of equal to or greater than about 800 h;alternatively, equal to or greater than about 2,000 h; alternatively,equal to or greater than about 5,000 h; alternatively equal to orgreater than about 10,000 h, when tested in accordance with ASTM F1473,wherein the resistance to slow crack growth is defined as thepolyethylene notch tensile test (PENT) failure time.

In an eighty-third aspect that can be in combination with any of thefirst to the eighty-second aspects, the polyethylene resin B can have aresistance to slow crack growth of equal to or greater than about 8,760h; alternatively, equal to or greater than about 10,000 h;alternatively, equal to or greater than about 15,000 h; alternatively,equal to or greater than about 25,000 h; alternatively, equal to orgreater than about 50,000 h; alternatively, equal to or greater thanabout 100,000 h; alternatively, equal to or greater than about 500,000h, when tested in accordance with ISO 16770 at 80° C. and 6 MPa, whereinthe resistance to slow crack growth is defined as the full notch creeptest (FNCT) failure time.

In an eighty-fourth aspect that can be in combination with any of thefirst to the eighty-third aspects, the polyethylene resin B can have aresistance to slow crack growth of equal to or greater than about 100 h;alternatively, equal to or greater than about 500 h; alternatively,equal to or greater than about 1,000 h; alternatively, equal to orgreater than about 5,000 h; alternatively equal to or greater than about10,000 h; alternatively equal to or greater than about 15,000 h, whentested in accordance with ISO 13479:2009(E) at 4.6 MPa, wherein theresistance to slow crack growth is defined as the notched pipe test(NPT) failure time.

In an eighty-fifth aspect that can be in combination with any of thefirst to the eighty-fourth aspects, the polyethylene resin B can have aviscous relaxation time of from about 0.5 s to about 7.5 s.

In an eighty-sixth aspect that can be in combination with any of thefirst to the eighty-fifth aspects, the polyethylene resin B can have anη₀ (eta_0) of equal to or greater than about 0.7×10⁵ Pa-s;alternatively, equal to or greater than about 1.0×10⁵ Pa-s;alternatively, from about 0.7×10⁵ Pa-s to about 2.0×10⁶ Pa-s.

In an eighty-seventh aspect that can be in combination with any of thefirst to the eighty-sixth aspects, the polyethylene resin B can have anη₂₅₁ (eta_251) of less than about 1.5×10³ Pa-s.

In an eighty-eighth aspect that can be in combination with any of thefirst to the eighty-seventh aspects, the polyethylene resin B can have astorage modulus (G′) of from about 225,000 Pa to about 325,000 Pa,wherein G′ is measured at 190° C. and 251 rad/s in accordance with ASTMD4440.

In an eighty-ninth aspect that can be in combination with any of thefirst to the eighty-eighth aspects, the polyethylene resin B can have aloss modulus (G″) of from about 100,000 Pa to about 200.00 Pa, whereinG″ is measured at 190° C. and 251 rad/s in accordance with ASTM D4440.

In a ninetieth aspect that can be in combination with any of the firstto the eighty-ninth aspects, the polyethylene resin B can have a tan δof from about 0.3 to about 0.7; wherein tan δ is the ratio of the lossmodulus (G″) to storage modulus (G′), wherein G″ and G′ are measured at190° C. and 251 rad/s in accordance with ASTM D4440.

In a ninety-first aspect that can be in combination with any of thefirst to the ninetieth aspects, the polyethylene resin B is made by aprocess described herein.

In a first aspect, polyethylene resin C can comprise the firstpolyolefin made in polymerization zone 112 of the first reactor 100, thesecond polyolefin made in the polymerization zone 321 of the riser 320of the MZCR 300, and the third polyolefin made in the polymerizationzone 341 of the downcomer 340 of the MZCR 300.

In a second aspect that can be in combination with the first aspect, thefirst polyolefin in polyethylene resin C can be a low molecular weight(LMW) component of the multimodal polyolefin, the second polyolefin inpolyethylene resin C can be an intermediate molecular weight (IMW)component of the multimodal polyolefin, and the third polyolefin inpolyethylene resin C can be a high molecular weight component (HMW) ofthe multimodal polyolefin.

In a third aspect that can be in combination with any of the first andthe second aspects, the first polyolefin (e.g., the LMW component) inpolyethylene resin C that is produced in the polymerization zone 112 ofthe first reactor 100 can be a lower molecular weight polyethylene, thesecond polyolefin (e.g., the IMW component) in polyethylene resin C thatis produced in the polymerization zone 321 of the riser 320, the thirdpolyolefin (e.g., the HMW component) in polyethylene resin C that isproduced in the polymerization zone 341 of the downcomer 340 can be ahigher molecular weight polyethylene, or combinations thereof.

In a fourth aspect that can be in combination with any of the first tothe third aspects, the LMW component is present in polyethylene resin Cin an amount of from about 40 wt. % to about 60 wt. %.

In a fifth aspect that can be in combination with any of the first tothe fourth aspects, the IMW component is present in polyethylene resin Cin an amount of from about 5 wt. % to about 15 wt. %.

In a sixth aspect that can be in combination with any of the first tothe fifth aspects, the HMW component is present in polyethylene resin Cin an amount of from about 30 wt. % to about 50 wt. %.

In a seventh aspect that can be in combination with any of the first tothe sixth aspects, the LMW component in polyethylene resin C has aweight average molecular weight of from about 25 kg/mol to about 65kg/mol.

In an eighth aspect that can be in combination with any of the first tothe seventh aspects, the IMW component in polyethylene resin C has aweight average molecular weight of from about 100 kg/mol to about 200kg/mol.

In a ninth aspect that can be in combination with any of the first tothe eighth aspects, the HMW component in polyethylene resin C has weightaverage molecular weight of from about 400 kg/mol to about 925 kg/mol.

In a tenth aspect that can be in combination with any of the first tothe ninth aspects, the LMW component in polyethylene resin C has a shortchain branching content of from about 0 to about 2 short chain branchesper 1,000 carbon atoms.

In an eleventh aspect that can be in combination with any of the firstto the tenth aspects, the IMW component in polyethylene resin C has ashort chain branching content of from about 0.1 to about 5 short chainbranches per 1,000 carbon atoms.

In a twelfth aspect that can be in combination with any of the first tothe eleventh aspects, the HMW component in polyethylene resin C has ashort chain branching content of from about 2 to about 12 short chainbranches per 1,000 carbon atoms.

In a thirteenth aspect that can be in combination with any of the firstto the twelfth aspects, the polyethylene resin C has a resistance toslow crack growth of equal to or greater than about 3,000 h, when testedin accordance with ASTM F1473, wherein the resistance to slow crackgrowth is defined as the polyethylene notch tensile test (PENT) failuretime.

In a fourteenth aspect that can be in combination with any of the firstto the thirteenth aspects, the weight average molecular weight of theHMW in polyethylene resin C is greater than the weight average molecularweight of the IMW.

In a fifteenth aspect that can be in combination with any of the firstto the fourteenth aspects, the polyethylene resin C is a trimodalpolyethylene resin.

In a sixteenth aspect that can be in combination with any of the firstto the fifteenth aspects, polyethylene resin C can have a resistance toslow crack growth of equal to or greater than about 8,760 h, when testedin accordance with ISO 16770 at 80° C. and 6 MPa, wherein the resistanceto slow crack growth is defined as the full notch creep test (FNCT)failure time.

In a seventeenth aspect that can be in combination with any of the firstto the sixteenth aspects, polyethylene resin C has a resistance to slowcrack growth of equal to or greater than about 1,000 h, when tested inaccordance with ISO 13479:2009(E) at 4.6 MPa, wherein the resistance toslow crack growth is defined as the notched pipe test (NPT) failuretime.

In an eighteenth aspect that can be in combination with any of the firstto the seventeenth aspects, polyethylene resin C has a weight averagemolecular weight (M_(w)) of from about 200 kg/mol to about 400 kg/mol.

In a nineteenth aspect that can be in combination with any of the firstto the eighteenth aspects, polyethylene resin C has a number averagemolecular weight (M_(n)) of from about 7.5 kg/mol to about 20 kg/mol.

In a twentieth aspect that can be in combination with any of the firstto the nineteenth aspects, polyethylene resin C has a z-averagemolecular weight (M_(z)) of from about 1,000 kg/mol to about 3,300kg/mol.

In a twenty-first aspect that can be in combination with any of thefirst to the twentieth aspects, polyethylene resin C has an η₀ (eta_0)of equal to or greater than about 1.0×10⁵ Pa-s.

In a twenty-second aspect that can be in combination with any of thefirst to the twenty-first aspects, polyethylene resin C is made by aprocess described herein.

In a first aspect, polyethylene resin D can comprise the firstpolyolefin made in polymerization zone 112 of the first reactor 100, thesecond polyolefin made in the polymerization zone 321 of the riser 320of the MZCR 300, and the third polyolefin made in the polymerizationzone 341 of the downcomer 340 of the MZCR 300.

In a second aspect that can be in combination with the first aspect, thefirst polyolefin in polyethylene resin D can be a low molecular weight(LMW) component of the multimodal polyolefin, the second polyolefin inpolyethylene resin D can be an intermediate molecular weight (IMW)component of the multimodal polyolefin, and the third polyolefin inpolyethylene resin D can be a high molecular weight component (HMW) ofthe multimodal polyolefin.

In a third aspect that can be in combination with any of the first andthe second aspects, the first polyolefin (e.g., the LMW component) inpolyethylene resin D that is produced in the polymerization zone 112 ofthe first reactor 100 can be a lower molecular weight polyethylene, thesecond polyolefin (e.g., the IMW component) in polyethylene resin D thatis produced in the polymerization zone 321 of the riser 320, the thirdpolyolefin (e.g., the HMW component) in polyethylene resin D that isproduced in the polymerization zone 341 of the downcomer 340 can be ahigher molecular weight polyethylene, or combinations thereof.

In a fourth aspect that can be in combination with any of the first tothe third aspects, the LMW component is present in polyethylene resin Din an amount of from about 40 wt. % to about 60 wt. %.

In a fifth aspect that can be in combination with any of the first tothe fourth aspects, the IMW component is present in polyethylene resin Din an amount of from about 5 wt. % to about 15 wt. %.

In a sixth aspect that can be in combination with any of the first tothe fifth aspects, the HMW component is present in polyethylene resin Din an amount of from about 30 wt. % to about 50 wt. %.

In a seventh aspect that can be in combination with any of the first tothe sixth aspects, the LMW component in polyethylene resin D has aweight average molecular weight of from about 30 kg/mol to about 50kg/mol.

In an eighth aspect that can be in combination with any of the first tothe seventh aspects, the IMW component in polyethylene resin D has aweight average molecular weight of from about 90 kg/mol to about 150kg/mol.

In a ninth aspect that can be in combination with any of the first tothe eighth aspects, the HMW component in polyethylene resin D has weightaverage molecular weight of from about 450 kg/mol to about 750 kg/mol.

In a tenth aspect that can be in combination with any of the first tothe ninth aspects, the LMW component in polyethylene resin D has a shortchain branching content of from about 0.1 to about 2 short chainbranches per 1,000 carbon atoms.

In an eleventh aspect that can be in combination with any of the firstto the tenth aspects, the IMW component in polyethylene resin D has ashort chain branching content of from about 0.1 to about 5 short chainbranches per 1,000 carbon atoms.

In a twelfth aspect that can be in combination with any of the first tothe eleventh aspects, the HMW component in polyethylene resin D has ashort chain branching content of from about 2 to about 10 short chainbranches per 1,000 carbon atoms.

In a thirteenth aspect that can be in combination with any of the firstto the twelfth aspects, the polyethylene resin D has a tensile strengthin the machine direction (MD) of greater than about 13,000 psi (89.6MPa), when tested in accordance with ASTM D638 at 90 MPa.

In a fourteenth aspect that can be in combination with any of the firstto the thirteenth aspects, the polyethylene resin D is a trimodalpolyethylene resin.

In a fifteenth aspect that can be in combination with any of the firstto the fourteenth aspects, the polyethylene resin D has a tensilestrength in the transverse direction (TD) of greater than about 6,000psi (about 41.4 MPa), when tested in accordance with ASTM D638 at 41MPa.

In a sixteenth aspect that can be in combination with any of the firstto the fifteenth aspects, the polyethylene resin D an η₀ (eta_0) ofequal to or greater than about 1.0×10⁵ Pa-s.

In a seventeenth aspect that can be in combination with any of the firstto the sixteenth aspects, polyethylene resin D is made by a processdescribed herein.

In a first aspect, polyethylene resin E is a Ziegler Natta-catalyzedpolyethylene resin.

In a second aspect that can be in combination with the first aspect,polyethylene resin E can comprise the first polyolefin made inpolymerization zone 112 of the first reactor 100, the second polyolefinmade in the polymerization zone 321 of the riser 320 of the MZCR 300,and the third polyolefin made in the polymerization zone 341 of thedowncomer 340 of the MZCR 300.

In a third aspect that can be in combination with any of the first andthe second aspects, the first polyolefin in polyethylene resin E can bea low molecular weight (LMW) component of the multimodal polyolefin, thesecond polyolefin in polyethylene resin E can be an intermediatemolecular weight (IMW) component of the multimodal polyolefin, and thethird polyolefin in polyethylene resin E can be a high molecular weightcomponent (HMW) of the multimodal polyolefin.

In a fourth aspect that can be in combination with any of the first tothe third aspects, the first polyolefin (e.g., the LMW component) inpolyethylene resin E that is produced in the polymerization zone 112 ofthe first reactor 100 can be a lower molecular weight polyethylene, thesecond polyolefin (e.g., the IMW component) in polyethylene resin E thatis produced in the polymerization zone 321 of the riser 320, the thirdpolyolefin (e.g., the HMW component) in polyethylene resin E that isproduced in the polymerization zone 341 of the downcomer 340 can be ahigher molecular weight polyethylene, or combinations thereof.

In a fifth aspect that can be in combination with any of the first tothe fourth aspects, the LMW component in polyethylene resin E isproduced in a first reaction zone in the substantial absence of acomonomer, wherein the LMW component is present in an amount of fromabout 20 wt. % to about 75 wt. %.

In a sixth aspect that can be in combination with any of the first tothe fifth aspects, the IMW component in polyethylene resin E is producedin a second reaction zone in the presence of a first amount of comonomerand a first amount of hydrogen.

In a seventh aspect that can be in combination with any of the first tothe sixth aspects, the IMW component is present in polyethylene resin Ein an amount of from about 5 wt. % to about 40 wt. %.

In an eighth aspect that can be in combination with any of the first tothe seventh aspects, the HMW component in polyethylene resin E isproduced in a third reaction zone in the presence of a second amount ofcomonomer and a second amount of hydrogen.

In a ninth aspect that can be in combination with any of the first tothe eighth aspects, the second amount of comonomer in polyethylene resinE is greater than the first amount of comonomer.

In a tenth aspect that can be in combination with any of the first tothe ninth aspects, first amount of hydrogen in polyethylene resin E isgreater than the second amount of hydrogen.

In an eleventh aspect that can be in combination with any of the firstto the tenth aspects, the HMW component is present in polyethylene resinE in an amount of from about 10 wt. % to about 60 wt. %.

In a twelfth aspect that can be in combination with any of the first tothe eleventh aspects, the LMW component in polyethylene resin E has aweight average molecular weight of from about 20 kg/mol to about 150kg/mol.

In a thirteenth aspect that can be in combination with any of the firstto the twelfth aspects, the IMW component in polyethylene resin E has aweight average molecular weight of from about 85 kg/mol to about 350kg/mol.

In a fourteenth aspect that can be in combination with any of the firstto the thirteenth aspects, the HMW component in polyethylene resin E hasweight average molecular weight of greater than about 350 kg/mol.

In a fifteenth aspect that can be in combination with any of the firstto the fourteenth aspects, the weight average molecular weight of theIMW component in polyethylene resin E is greater than the weight averagemolecular weight of the LMW component.

In a sixteenth aspect that can be in combination with any of the firstto the fifteenth aspects, the LMW component in polyethylene resin E hasa short chain branching content of from about 0 to about 5 short chainbranches per 1,000 carbon atoms.

In a seventeenth aspect that can be in combination with any of the firstto the sixteenth aspects, the IMW component in polyethylene resin E hasa short chain branching content of from about 0.1 to about 10 shortchain branches per 1,000 carbon atoms.

In an eighteenth aspect that can be in combination with any of the firstto the seventeenth aspects, the HMW component in polyethylene resin Ehas a short chain branching content of from about 1 to about 15 shortchain branches per 1,000 carbon atoms.

In a nineteenth aspect that can be in combination with any of the firstto the eighteenth aspects, the polyethylene resin E has an η₂₅₁(eta_251) of less than about 1.5×10³ Pa-s.

In a twentieth aspect that can be in combination with any of the firstto the nineteenth aspects, the polyethylene resin E is a trimodalpolyethylene resin.

In a twenty-first aspect that can be in combination with any of thefirst to the twentieth aspects, a first reactor in polyethylene resin Ecomprises the first reaction zone.

In a twenty-second aspect that can be in combination with any of thefirst to the twenty-first aspects, the first reaction zone inpolyethylene resin E comprises a gas phase reaction zone.

In a twenty-third aspect that can be in combination with any of thefirst to the twenty-second aspects, a second reactor in polyethyleneresin E comprises the second reaction zone and the third reaction zone.

In a twenty-fourth aspect that can be in combination with any of thefirst to the twenty-third aspects, the second reaction zone inpolyethylene resin E comprises a riser.

In a twenty-fifth aspect that can be in combination with any of thefirst to the twenty-fourth aspects, the second reaction zone inpolyethylene resin E comprises a fast fluidization reaction zone.

In a twenty-sixth aspect that can be in combination with any of thefirst to the twenty-fifth aspects, the third reaction zone inpolyethylene resin E comprises a downcomer.

In a twenty-seventh aspect that can be in combination with any of thefirst to the twenty-sixth aspects, the third reaction zone inpolyethylene resin E comprises a plug flow reaction zone.

In a first aspect, polyethylene resin F is a Ziegler Natta-catalyzedpolyethylene resin.

In a second aspect that can be in combination with the first aspect,polyethylene resin F can comprise the first polyolefin made inpolymerization zone 112 of the first reactor 100, the second polyolefinmade in the polymerization zone 321 of the riser 320 of the MZCR 300,and the third polyolefin made in the polymerization zone 341 of thedowncomer 340 of the MZCR 300.

In a third aspect that can be in combination with any of the first andthe second aspects, the first polyolefin in polyethylene resin F can bea low molecular weight (LMW) component of the multimodal polyolefin, thesecond polyolefin in polyethylene resin F can be an intermediatemolecular weight (IMW) component of the multimodal polyolefin, and thethird polyolefin in polyethylene resin F can be a high molecular weightcomponent (HMW) of the multimodal polyolefin.

In a fourth aspect that can be in combination with any of the first tothe third aspects, the first polyolefin (e.g., the LMW component) inpolyethylene resin F that is produced in the polymerization zone 112 ofthe first reactor 100 can be a lower molecular weight polyethylene, thesecond polyolefin (e.g., the IMW component) in polyethylene resin F thatis produced in the polymerization zone 321 of the riser 320, the thirdpolyolefin (e.g., the HMW component) in polyethylene resin F that isproduced in the polymerization zone 341 of the downcomer 340 can be ahigher molecular weight polyethylene, or combinations thereof.

In a fifth aspect that can be in combination with any of the first tothe fourth aspects, the LMW component in polyethylene resin F isproduced in a gas phase reaction zone in the substantial absence of acomonomer,

In a sixth aspect that can be in combination with any of the first tothe fifth aspects, the LMW component is present in polyethylene resin Fin an amount of from about 20 wt. % to about 75 wt. %.

In a seventh aspect that can be in combination with any of the first tothe sixth aspects, the IMW component in polyethylene resin F is producedin a fast fluidization reaction zone in the presence of a first amountof comonomer and a first amount of hydrogen.

In an eighth aspect that can be in combination with any of the first tothe seventh aspects, the IMW component is present in polyethylene resinF in an amount of from about 5 wt. % to about 40 wt. %.

In a ninth aspect that can be in combination with any of the first tothe eighth aspects, the HMW component in polyethylene resin F isproduced in a plug flow reaction zone in the presence of a second amountof comonomer and a second amount of hydrogen.

In a tenth aspect that can be in combination with any of the first tothe ninth aspects, the second amount of comonomer in polyethylene resinF is greater than the first amount of comonomer.

In an eleventh aspect that can be in combination with any of the firstto the tenth aspects, first amount of hydrogen in polyethylene resin Fis greater than the second amount of hydrogen.

In a twelfth aspect that can be in combination with any of the first tothe eleventh aspects, the HMW component is present in polyethylene resinF in an amount of from about 10 wt. % to about 60 wt. %.

In a thirteenth aspect that can be in combination with any of the firstto the twelfth aspects, the LMW component in polyethylene resin F has aweight average molecular weight of from about 20 kg/mol to about 150kg/mol.

In a fourteenth aspect that can be in combination with any of the firstto the thirteenth aspects, the IMW component in polyethylene resin F hasa weight average molecular weight of from about 85 kg/mol to about 350kg/mol.

In a fifteenth aspect that can be in combination with any of the firstto the fourteenth aspects, the HMW component in polyethylene resin F hasweight average molecular weight of greater than about 350 kg/mol.

In a sixteenth aspect that can be in combination with any of the firstto the fifteenth aspects, the weight average molecular weight of the IMWcomponent in polyethylene resin F is greater than the weight averagemolecular weight of the LMW component.

In a seventeenth aspect that can be in combination with any of the firstto the sixteenth aspects, the LMW component in polyethylene resin F hasa short chain branching content of from about 0 to about 5 short chainbranches per 1,000 carbon atoms.

In an eighteenth aspect that can be in combination with any of the firstto the seventeenth aspects, the IMW component in polyethylene resin Fhas a short chain branching content of from about 0.1 to about 10 shortchain branches per 1,000 carbon atoms.

In a nineteenth aspect that can be in combination with any of the firstto the eighteenth aspects, the HMW component in polyethylene resin F hasa short chain branching content of from about 1 to about 15 short chainbranches per 1,000 carbon atoms.

In a twentieth aspect that can be in combination with any of the firstto the nineteenth aspects, the polyethylene resin F has an η₂₅₁(eta_251) of less than about 1.5×10³ Pa-s.

In a twenty-first aspect that can be in combination with any of thefirst to the twentieth aspects, the polyethylene resin F is a trimodalpolyethylene resin.

In a twenty-second aspect that can be in combination with any of thefirst to the twenty-first aspects, a first reactor in polyethylene resinF comprises the gas phase reaction zone.

In a twenty-third aspect that can be in combination with any of thefirst to the twenty-second aspects, a second reactor in polyethyleneresin F comprises a riser and a downcomer.

In a twenty-fourth aspect that can be in combination with any of thefirst to the twenty-third aspects, the riser in polyethylene resin Fcomprises the fast fluidization reaction zone, and wherein the downcomercomprises the plug flow reaction zone.

At least one embodiment is disclosed and variations, combinations,and/or modifications of the embodiment(s) and/or features of theembodiment(s) made by a person having ordinary skill in the art arewithin the scope of the disclosure. Alternative embodiments that resultfrom combining, integrating, and/or omitting features of theembodiment(s) are also within the scope of the disclosure. Wherenumerical ranges or limitations are expressly stated, such expressranges or limitations should be understood to include iterative rangesor limitations of like magnitude falling within the expressly statedranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4,etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example,whenever a numerical range with a lower limit, R_(l), and an upperlimit, R_(u), is disclosed, any number falling within the range isspecifically disclosed. In particular, the following numbers within therange are specifically disclosed: R=R_(l)+k*(R_(u)−R_(l)), wherein k isa variable ranging from 1 percent to 100 percent with a 1 percentincrement, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5percent, . . . 50 percent, 51 percent, 52 percent . . . 95 percent, 96percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover,any numerical range defined by two R numbers as defined in the above isalso specifically disclosed. Use of the term “optionally” with respectto any element of a claim means that the element is required, oralternatively, the element is not required, both alternatives beingwithin the scope of the claim. Use of broader terms such as comprises,includes, and having should be understood to provide support fornarrower terms such as consisting of, consisting essentially of, andcomprised substantially of. Accordingly, the scope of protection is notlimited by the description set out above but is defined by the claimsthat follow, that scope including all equivalents of the subject matterof the claims. Each and every claim is incorporated as furtherdisclosure into the specification and the claims are embodiment(s) ofthe disclosed inventive subject matter. The discussion of a reference inthe disclosure is not an admission that it is prior art, especially anyreference that has a publication date after the priority date of thisapplication. The disclosure of all patents, patent applications, andpublications cited in the disclosure are hereby incorporated byreference, to the extent that they provide exemplary, procedural orother details supplementary to the disclosure.

What is claimed is:
 1. A process for producing a multimodal polyolefin,the process comprising: polymerizing ethylene in a first reactor toproduce a first polyolefin; receiving the first polyolefin from thefirst reactor into a second reactor comprising a riser, an upperconduit, a separator, a downcomer, a lower conduit, and optionally aliquid barrier; polymerizing ethylene in a first reaction mixturecontaining the first polyolefin in the riser of the second reactor toproduce a second polyolefin; passing the first reaction mixture throughthe upper conduit from the riser to the separator; recovering, in theseparator, the first polyolefin and the second polyolefin from the firstreaction mixture; passing the first polyolefin and the second polyolefinfrom the separator into the downcomer, optionally via the liquidbarrier; polymerizing ethylene in a second reaction mixture containingthe first polyolefin and the second polyolefin in the downcomer toproduce the multimodal polyolefin comprising the first polyolefin, thesecond polyolefin, and a third polyolefin; passing a first portion ofthe second reaction mixture through the lower conduit from the downcomerto the riser; and discharging, through a take-off valve, a secondportion of the second reaction mixture from the downcomer, wherein thesecond reaction mixture comprises greater than 50 wt. % of solidpolyolefin particles based on a total weight of the second reactionmixture.
 2. A process for producing a multimodal polyolefin, the processcomprising: polymerizing ethylene in a first reactor to produce a firstpolyolefin; receiving the first polyolefin from the first reactor into asecond reactor comprising a riser, an upper conduit, a separator, adowncomer, a lower conduit, and optionally a liquid barrier;polymerizing ethylene in a first reaction mixture containing the firstpolyolefin in the riser of the second reactor to produce a secondpolyolefin; passing the first reaction mixture through the upper conduitfrom the riser to the separator; recovering, in the separator, the firstpolyolefin and the second polyolefin from the first reaction mixture;passing the first polyolefin and the second polyolefin from theseparator into the downcomer, optionally via the liquid barrier;polymerizing ethylene in a second reaction mixture containing the firstpolyolefin and the second polyolefin in the downcomer to produce themultimodal polyolefin comprising the first polyolefin, the secondpolyolefin, and a third polyolefin; passing a first portion of thesecond reaction mixture through the lower conduit from the downcomer tothe riser; discharging, through a take-off valve, a second portion ofthe second reaction mixture from the downcomer; and creating fastfluidization conditions in the riser by providing i) an eductor having asuction inlet fluidly connected to the downcomer or to the lower conduitor ii) a standpipe fluidly connected to the lower conduit or to theriser.
 3. A process for producing a multimodal polyolefin, the processcomprising: polymerizing ethylene in a first reactor to produce a firstpolyolefin; receiving the first polyolefin from the first reactor into asecond reactor comprising a riser, an upper conduit, a separator, adowncomer, a lower conduit, and optionally a liquid barrier;polymerizing ethylene in a first reaction mixture containing the firstpolyolefin in the riser of the second reactor to produce a secondpolyolefin; passing the first reaction mixture through the upper conduitfrom the riser to the separator; recovering, in the separator, the firstpolyolefin and the second polyolefin from the first reaction mixture;passing the first polyolefin and the second polyolefin from theseparator into the downcomer, optionally via the liquid barrier;polymerizing ethylene in a second reaction mixture containing the firstpolyolefin and the second polyolefin in the downcomer to produce themultimodal polyolefin comprising the first polyolefin, the secondpolyolefin, and a third polyolefin; passing a first portion of thesecond reaction mixture through the lower conduit from the downcomer tothe riser; and discharging, through a take-off valve, a second portionof the second reaction mixture from the downcomer, wherein the firstreactor is a fluidized bed reactor, wherein receiving the firstpolyolefin from the first reactor into the second reactor the processcomprises: receiving the first polyolefin and a gas mixture from asettling leg, a lock hopper, or a continuous take-off valve that iscoupled to the first reactor into a separation vessel; and separating,by the separation vessel, the first polyolefin from the gas mixture,wherein receiving the first polyolefin from the first reactor into thesecond reactor the process further comprises: analyzing a sample of thefirst polyolefin obtained via a sample take-off conduit fluidlyconnected to the settling leg, the lock hopper, or the continuoustake-off valve.
 4. The process of claim 1, 2, or 3, wherein the firstpolyolefin is a low molecular weight (LMW) component of the multimodalpolyolefin, the second polyolefin is an intermediate molecular weight(IMW) component of the multimodal polyolefin, and the third polyolefinis a high molecular weight component (HMW) of the multimodal polyolefin.5. The process of claim 4, further comprising: circulating themultimodal polyolefin in the second reactor from 1 to about 250 cyclesbefore discharging the second portion of the second reaction mixturefrom the downcomer.
 6. The process of claim 4, wherein a residence timeof the second reaction mixture during a single pass through thedowncomer is in a range of from about 5 seconds to about 15 minutes. 7.The process of claim 6, wherein a residence time of the first reactionmixture during a single pass through the riser is in a range of fromabout 1 second to about 5 minutes.
 8. The process of claim 4, whereinrecovering, in the separator, the first polyolefin and the secondpolyolefin from the first reaction mixture comprises: separating, by theseparator, 99 wt. % or more of solid particles in the first reactionmixture from gas in the first reaction mixture.
 9. The process of claim8, wherein the separator is a cyclone separator.
 10. The process ofclaim 9, wherein the cyclone separator is a high efficiency cycloneseparator, wherein the 99 wt. % or more of the solid particles that areseparated have a particle size of greater than about 10 μm.
 11. Theprocess of claim 4, further comprising: adding a reactor deactivationagent to the second reactor, wherein the reactor deactivation agent isconfigured to moderate or kill polymerization reactions in the riser,the downcomer, or both the riser and the downcomer.
 12. The process ofclaim 11, wherein the reactor deactivation agent is not water.
 13. Theprocess of claim 4, further comprising: injecting comonomer into thedowncomer, wherein the third polyolefin is a copolymer.
 14. The processof claim 4, further comprising: analyzing a sample of the first reactionmixture at one or more locations in the second reactor to determine aconcentration of gas, liquid, or solid in the first reaction mixture,and to determine a concentration of monomer, comonomer, diluent,hydrogen, inert component, or polymer in the first reaction mixture. 15.The process of claim 14, further comprising: analyzing a sample of thesecond reaction mixture at one or more locations in the second reactorto determine a concentration of gas, liquid, or solid in the secondreaction mixture, and to determine a concentration of monomer,comonomer, diluent, hydrogen, inert component, or polymer in the secondreaction mixture.
 16. The process of claim 4, further comprising addingor removing heat from the riser or the downcomer.
 17. The process ofclaim 4, further comprising: maintaining a Dean number (D_(n)) of thefirst reaction mixture in an elbow connector to be higher than3,000,000, where D_(n)=ρVd/μ*(d/2R_(c))^(1/2), where ρ is a density ofthe first reaction mixture, V is a circulation velocity of the firstreaction mixture, μ is a dynamic viscosity of the first reactionmixture, d is an inner diameter of the elbow connector, and R_(c) is aninner curvature of the elbow connector, wherein the elbow connector isconnected to the riser and to the upper conduit.
 18. The process ofclaim 4, further comprising: maintaining a Dean number (D_(n)) of thesecond reaction mixture in an elbow connector to be higher than3,000,000, where D_(n)=ρVd/μ*(d/2R_(c))^(1/2), where ρ is a density ofthe second reaction mixture, V is a circulation velocity of the secondreaction mixture, μ is a dynamic viscosity of the second reactionmixture, d is an inner diameter of the elbow connector, and R_(c) is aninner curvature of the elbow connector, wherein the elbow connector isconnected to i) the riser and the lower conduit or ii) the downcomer andthe lower conduit.
 19. The process of claim 4, further comprising:measuring a density of the first reaction mixture in the riser.
 20. Theprocess of claim 1 or claim 2, wherein the first polyolefin is a lowmolecular weight (LMW) component of the multimodal polyolefin, thesecond polyolefin is an intermediate molecular weight (IMW) component ofthe multimodal polyolefin, and the third polyolefin is a high molecularweight component (HMW) of the multimodal polyolefin, wherein the firstreactor is a loop slurry reactor, a fluidized bed reactor, an autoclavereactor, a tubular reactor, a horizontal gas phase reactor, a continuousstirred-tank reactor, or a solution reactor.
 21. The process of claim 4,wherein the take-off valve is a continuous take-off valve.
 22. Theprocess of claim 21, wherein the continuous take-off valve has an innerdiameter in a range of about 0.5 inches to about 3 inches.
 23. Amultimodal polyolefin resin produced by the process of claim 1, 2, or 3,wherein the multimodal polyolefin resin comprises the first polyolefin,the second polyolefin, and the third polyolefin, wherein the firstpolyolefin is a low molecular weight (LMW) component of the multimodalpolyolefin resin, the second polyolefin is an intermediate molecularweight (IMW) component of the multimodal polyolefin resin, and the thirdpolyolefin is a high molecular weight component (HMW) of the multimodalpolyolefin resin, wherein the multimodal polyolefin resin has aresistance to slow crack growth of at least 100% as determined inaccordance with ASTM F1473, wherein the resistance to slow crack growthis defined as the polyethylene notch tensile test (PENT) failure time.